We're not learning things about whether you should or shouldn't take the vaccine—it's overwhelmingly clear that you should. The risk from natural infection with COVID greatly outweighs any slight risk from COVID-19 vaccines. We are continuing to learn about the effectiveness of COVID-19 vaccines with different variants that emerge and how best to use these vaccines. We are not suddenly going to learn about new safety problems. For more information, listen to The Osterholm Update: COVID-19, Episode 64: Straight Talk (37:00).
Wear a mask. Wear the best mask available to you. Wear a mask that fits over your nose and snugly around your mouth. Ideally, wear an N95, KN95, or respiratory protection of a similar caliber. For more information, listen to The Osterholm Update: COVID-19, Episode 64: Straight Talk (52:30).
CIDRAP typically refers to the disease as COVID-19 and the virus that causes the disease as SARS-CoV-2. You may, however, see these terms used interchangeably.
There is no evidence of seasonality for COVID-19. For more information, listen to the Osterholm Update: COVID-19: Episode 56: From Checkers to Chess (10:15) and the Osterholm Update: COVID-19, Episode 58: A Year at Sea (18:20), The Osterholm Update: COVID-19, Episode 60: A Formidable Foe (5:00 and 13:00), The Osterholm Update: COVID-19, Episode 61: Divided by Delta (28:00) and The Osterholm Update: COVID-19, Episode 62: Untangling the Data (29:00).
It is important to base new policy on the variants posing the risk at the current time. Data from months ago when the wild-type or a different variant was dominant may no longer apply. Collecting the data is not enough; the data need to be shared as well. For example, there are emerging data showing that vaccinated people who become infected with the Delta variant of SARS-CoV-2 can spread it to others, which is different from data observed in the context of the Alpha variant. For more information, listen to The Osterholm Update: COVID-19, Episode 62: Untangling the Data (49:00).
There is strong evidence that transmission of SARS-CoV-2 can occur from aerosol exposure. The World Health Organization states "Current evidence suggests that the virus spreads mainly between people who are in close contact with each other, typically within 1 metre (short-range). A person can be infected when aerosols or droplets containing the virus are inhaled or come directly into contact with the eyes, nose, or mouth. The virus can also spread in poorly ventilated and/or crowded indoor settings, where people tend to spend longer periods of time. This is because aerosols remain suspended in the air or travel farther than 1 metre (long-range)." The CDC has followed suit in acknowledging the role of aerosols in the spread of SARS-CoV-2.
The infectious dose of COVID-19 is not yet fully understood. Global experts are working together to determine this key piece of understanding about SARS-CoV-2 in humans. Once this is understood, we will have a better idea of what duration or distance of activities pose a low versus high risk. CIDRAP will share this information as soon as it is available.
Many of the individuals who transmit SARS-CoV-2 do so when they're presymptomatic, not yet sick, or potentially completely asymptomatic (have no symptoms). More studies are needed to learn more. For more information, listen to the Osterholm Update: COVID-19, Episode 11: Driven by the Data (17:00).
Variants of SARS-CoV-2, which are naturally mutated strains now infecting people, have increased, and it takes time to know how they will affect the spread of COVID-19, severity of illness, or effectiveness of vaccines. Coronaviruses are known to go through frequent mutations over time, so the appearance of variants is not unexpected but is still concerning. More variants are likely to appear. The most concerning changes are those affecting the spike protein, which are the parts onthe virus's surface that our immune systems respond to in order to keep the virus from entering our cells. There are a number of variants that health officials are monitoring.
The Alpha variant (also known as B117 or the UK variant) is more infectious than earlier forms of the virus, possibly by 50% to 70%. This variant has already been found in many countries, including many US states.
Another variant, Beta (B1351) was first identified in South Africa and is also associated with increased transmission and higher viral load. Officials have confirmed yet another variant, Gamma (P1, first detected in Brazil). Both the Beta and Gamma variants have mutational changes that could lower the effectiveness of immune-boosting therapies or vaccines, but details are as yet unknown. So far, it does not appear these variants are spreading significantly outside of the current locations in the same way that Alpha spread.
The Delta variant (B1617.2), first identified in India, is likely more transmissible and is driving cases worldwide. Early reports showed Delta to be at least 40% more infectious than the Alpha variant, which is estimated to be 50% to 70% more infectious than previous strains.
For a list of the variants of concern and variants of interest, see the WHO website.
Evidence suggests that the difference between people who are symptomatic from those who are asymptomatic is primarily host characteristics, such as age, and not from behaviors, such as mask use. There is no evidence that SARS-CoV-2 dose in animal studies actually affects their infection being mild or severe, though disease severity differs by age or the genetics of the and the comorbidities of the animals. Old, overweight macaques with diabetes that are infected with a low dose can still come down with very, very serious disease. In contrast, young macaques, even healthy ones infected with higher doses, often have a very mild, if asymptomatic infection. So the dose may actually be even less important than who is getting infected. For more information on why some recently published studies are unfounded and potentially dangerous, listen to the Osterholm Update: COVID-19, Episode 23: COVID-19 and Mental Health (21:30)
COVID-19 is not like influenza in many ways. The pattern of COVID-19 infections to date suggests that this pandemic will not follow a pattern like flu, but rather be more like a forest fire that burns whenever there is fuel. For this virus, fuel would be potential hosts. Additionally, we know more about flu in humans than we do COVID-19. We have tests, antiviral drugs, and a scientific base for flu that doesn’t exist for SARS-CoV-2.
Modeling of COVID-19 spread and effects of interventions is fraught with issues due to the complexity and number of unknowns. These limitations mean many of these models require many assumptions that may render the models meaningless or even dangerous. For more information, see "Why it's so freaking hard to make a good COVID-19 model" or listen to the Osterholm Update: COVID-19, Episode 31: Pay to Prevail (18:30)
There is reason to think the death counts from COVID-19 are undercounts. There is no evidence that deaths unrelated to COVID-19 have been inappropriately attributed to the disease. Using an analogy from Megan, a podcast listener, “We know that some things increase the risk of wildfires and also increase the risk of wildfires becoming dangerous. For example, hot, dry weather accelerates fires. A longstanding drought makes the countryside extremely dry and a flammable tinderbox. High winds blow the flames and embers further afield. When a person has a comorbidity like heart disease, type two diabetes, obesity, COPD, it's kind of like when the landscape is extra vulnerable to bad wildfires due to heat, drought, or high winds. If a wildfire or COVID starts under these conditions, it's much more likely to become dangerous and even fatal. But the cause of death would still be COVID.” For more information, listen to the Osterholm Update: COVID-19, Episode 22: Pregnancy in a Pandemic (23:00)
The spread of COVID-19 is a function of distance, duration, and air circulation. Avoid the three C's: closed spaces, crowds, and close contact.
Ventilation is the key to reducing risk, which is why outdoor spaces involve a much lower risk of virus transmission. Outdoors is best, but any barrier such as a tent or awning could theoretically reduce the ventilation and therefore increase the risk of exposure. There are documented outbreaks from crowded outdoor events, so being outdoors is not without any risk. For more information, listen to the Osterholm Update: COVID-19, Episode 56: From Checkers to Chess (38:00).
Double masks are not clearly an improvement over a single mask, because protection is based on fit and filtration (how well viruses are filtered out). Doubling up masks may change the fit and increase leakage. N95 respirators are clearly the best in terms of preventing inward and outward leakage. Three-layer masks and neck gaiters worn properly (always over the nose) offer the most protection for the wearer and those around, but the protection is limited. Three-layer masks and neck gaiters buy the wearer time in acquiring an infectious dose, but they do not offer substantial protection and are not good for long periods. For more information, listen to the Osterholm Update: COVID-19, Episode 42: Calling an Audible (42:45) and the Osterholm Update: COVID-19, Episode 44: Hurricane Warning (37:00).
Wearing a cloth face covering is not permission to get close to others or go into crowds. It is merely an added layer of protection for both the wearer and others. Cloth masks and face coverings likely do not offer the same degree of protection as physical distancing, isolation, or limiting personal contact time. A cloth mask or face covering does very little to prevent the emission or inhalation of small particles; therefore, the level of protection may not be substantial. For more information, listen to the Osterholm Update: COVID-19, Special Episode: Masks and Science and the Osterholm Update: COVID-19, Episode 56: From Checkers to Chess (30:00).
Clear face shields are not a replacement for cloth face coverings or masks. The CDC states, "It is not known if face shields provide any benefit as source control to protect others from the spray of respiratory particles. CDC does not recommend use of face shields for normal everyday activities or as a substitute for cloth face coverings." For more information, listen to the Osterholm Update: COVID-19, Episode 19: No Time to Rest (36:35).
The science is unclear if 6 feet is sufficient to prevent the spread of COVID-19, although evidence suggests that 6 feet is not enough, and 3 feet is certainly not enough. Most published data on aerosol and droplet spread is not specific to SARS-CoV-2, but the science strongly points to longer distances than 6 feet, sometimes substantially more. For more information, see "Short-range airborne route dominates exposure of respiratory infection during close contact," "Theoretical analysis of the motion and evaporation of exhaled respiratory droplets of mixed composition," and "Study of SARS transmission via liquid droplets in air."
Two weeks after vaccination with the second dose of the Pfizer or Moderna vaccines or the only dose needed of the Johnson & Johnson vaccine, a person's risk of serious COVID-19 decreases substantially and also the likelihood of spreading COVID-19 to others. Therefore, the CDC has released guidance on what fully vaccinated people can do with lessened risk.
Because of the current rates of COVID-19 and circulating variants (virus strains that have mutated), continue to avoid non-essential domestic and international travel. While being fully vaccinated substantially reduces the risk of acquiring COVID-19, the protection is not perfect, especially in parts of the world where certain variants are circulating. If you do travel, follow CDC requirements and recommendations. Staying local is safer than traveling long distances. The most important aspect of staying safe is what a person does during travel. Indoor dining in restaurants, gatherings of several households, sharing transportation, and visiting public attractions are still higher-risk activities. For more information, listen to the Osterholm Update: COVID-19, Episode 50: Sitting in Limbo (41:00).
Vaccination and Herd Immunity
It is critical to get vaccinated when you can, since continued transmission leads to more virus evolution and more variants. For more information, listen to the Osterholm Update: COVID-19, Episode 42: Calling an Audible (21:00 and 41:00).
There are many vaccines that require multiple doses spaced out over months to achieve optimal and sustained protection for the virus they target. Early data suggest the COVID-19 vaccines will require additional doses to work as effectively as possible over time. To date, the most information is known about the Pfizer COVID-19 vaccine, because more Americans have received this type than any other. Likewise, the most information is known about how well the vaccines over time protect people that are older, high risk, and employed in healthcare because these were the first people to receive the vaccinations. This larger amount of data is a factor in why Pfizer recipients in these groups in the US were the first to be recommended to get "booster," or third, doses. For more information, listen to The Osterholm Update; COVID-19, Episode 71: Boosting the Vaccination Effort (21:45).
We don't know what herd immunity is with COVID-19, which is the point at which virus spread slows because enough people are protected from infection by having antibodies from either vaccination or infection. Remember, herd immunity does not stop transmission. And some key aspects of COVID-19 and herd immunity are rarely discussed. First, once immune doesn't mean always immune. We do not know how long protection from vaccination or natural infection lasts, but it appears that vaccination will require boosters for possibly waning immunity and variant coverage. Second, variants, such as B117, are so much more contagious that a population must have much higher level of protection to slow transmission. For more information, listen to The Osterholm Update: COVID-19, Episode 22: Pregnancy in a Pandemic (11:30) and The Osterholm Update: COVID-19, Episode 51: A Balancing Act (34:00).
Low- and middle-income country access to COVID vaccines is not just a humanitarian issue, it is a global public health issue. More infections means more opportunities for SARS-CoV-2 to mutate into new variants. It is in the best interest of the United States and other high-income countries to ensure access to vaccination worldwide. For more information, listen to the Osterholm Update: COVID-19, Episode 50: Sitting in Limbo (37:00).
Public health needs to be transparent about breakthrough cases—those that occur in vaccinated people. It is also important to not lump the mRNA platform vaccines (Moderna and Pfizer) with the adenovirus-platform single-dose vaccine (Johnson & Johnson). The data support that these are very good vaccines, but we expect breakthrough cases and deaths even in very effective vaccines. As more people are exposed to SARS-CoV-2, it is expected that more breakthrough cases will be observed. For more information, listen to the Osterholm Update: COVID-19, Episode 56: From Checkers to Chess (26:00).
A person does not need to feel awful in the days after COVID-19 vaccination for the vaccine to be working. It is not necessary to get antibody levels measured. For more information, listen to The Osterholm Update: COVID-19, Episode 51: A Balancing Act (30:30).
There are three vaccines approved for use in the United States—made by Moderna, Pfizer/BioNTech ("Pfizer," for simplicity), and Johnson & Johnson. All of the vaccines appear to offer impressive protection against severe illness and death, while having no serious safety concerns. It is inappropriate to compare their efficacy against other measures, such as mild or moderate infection, because of differences in research protocols and settings. For all of the vaccines, it is unknown how long any vaccine-provided protection lasts.
The Moderna and Pfizer vaccines are both two-dose mRNA vaccines. The Pfizer vaccine needs to be stored and transported at -94°F. The Moderna vaccine can be stored and transported at -4°F, which can be achieved in existing freezers. These mRNA vaccines can be tweaked for virus variants relatively quickly, which could prove to be important. For more information, listen to the Osterholm Update: COVID-19, Episode 32: Stop Swapping Air (24:00).
The Johnson & Johnson vaccine is a one-dose option that uses a different virus, specifically an adenovirus, as its "backbone." Genetic material from SARS-CoV-2 (the COVID-19 virus) is added to the adenovirus, which is modified so that it doesn't cause sickness. But your body will recognize the SARS-COV-2 genetic material on the adenovirus and produce an immune response against it. The Johnson & Johnson vaccine can be shipped and stored at regular refrigeration temperatures. The storage and single-dose requirements simplify the process. There have been reported cases of blood clots in recipients of this vaccine, so on Apr 23 the Food and Drug Administration added a caution about the vaccine. The warning notes that very rarely the Johnson & Johnson vaccine may cause blood clots in women ages 18 to 49. For more information on these blood clots and the US response, listen to The Osterholm Update: COVID-19, Episode 51: A Balancing Act (42:00).
A person can receive the COVID-19 vaccine and influenza vaccine at the same visit.
A vaccine without a vaccination does no good. The public health community needs to work on messaging to counteract claims of false side effects--those adverse events that are temporally related (merely by coincidence) to vaccination but unlikely to be caused by it. To explain further: In any given week, a certain number of people will have health issues or die. Once a large number of people get vaccinated, we expect to see heart attacks, strokes, and deaths after vaccination, as they would occur without vaccination. This does not mean that the vaccination caused these adverse events. Public health needs to be ready to communicate real versus false side effects. For more information, listen to The Osterholm Update: COVID-19, Episode 35: The Last Mile to the Last Inch (33:00)
Both the Pfizer and the Moderna vaccines use a messenger RNA (mRNA) platform. While this is a newer platform, there are previous data on them for other diseases and they appear very safe. We have had RNA vaccine trials in humans for cytomegalovirus, zika, influenza, rabies, and chikungunya. In addition, a large number of cancer vaccines and therapeutic approaches have been based on messenger RNA. So while this platform is newer, it is not without evidence of safety. For more information, listen to The Osterholm Update: COVID-19, Episode 34: The Best of Times and the Worst of Times (19:00).
Even though safe and effective vaccines are approved in the United States, it will not immediately end the pandemic. There will be manufacturing, distribution, and logistical issues. Which means it will take months, if not years, to achieve sustained herd immunity, if that is even possible. Remember that some of the vaccine regimens require two doses for full effectiveness, which would further slow the population-wide effects of a vaccine. We are in this for the long haul. COVID-19 is not going to miraculously disappear in 2021. For more information, listen to The Osterholm Update: COVID-19, Episode 25: Ripple Effects (17:30).
It is still critical that children and adults get routine vaccinations, such as measles, polio, and seasonal flu vaccines. For example, secondary outbreaks of measles or polio could cause significant death and disability in children. For more information on flu vaccination, listen to The Osterholm Update: COVID-19, Episode 24: Long-Haulers (35:27) and, on other vaccinations, listen to The Osterholm Update: COVID-19, Episode 25: Ripple Effects (31:30).
Hospitalizations and deaths are lagging indicators. People exposed today can be clinically ill in 5 to 6 days, perhaps admitted to the hospital five 5 to six 6 days after that, then a few may then be admitted to the intensive care unit, with a fair share of them spending days to weeks before ultimately dying. What we do now affects what is going to happen a month or more out. We need to act immediately to buy time until vaccines are available in sufficient supply. For more information, listen to the Osterholm Update: COVID-19, Episode 32: Stop Swapping Air (12:00).
Contact tracing is most effective when the incidence of infection in a given population is low and when cases and contacts can quickly and easily be identified. For more information, see CIDRAP’s Viewpoint report, "Contact tracing for COVID-19: Assessing needs, using a tailored approach."
It is important that control measures do not impede access to other types of healthcare. For more information, listen to The Osterholm Update: COVID-19, Episode 25: Ripple Effects (29:00).
There are many reported cases of long-term symptoms from people recovered from COVID-19. These people are called “long-haulers,” and many of them were never hospitalized. Public Health England’s (PHE’s) statement dated Sep 7, 2020, states, “Around 10% of mild coronavirus (COVID-19) cases who were not admitted to hospital have reported symptoms lasting more than 4 weeks. A number of hospitalised cases reported continuing symptoms for 8 or more weeks following discharge.” For the full PHE statement, see, "COVID-19: long-term health effects," and listen to The Osterholm Update: COVID-19, Episode 24: Long-Haulers (20:00).
Long-haulers are those with persistent health problems from COVID-19—a real problem for which knowledge is only beginning to build. Documented problems include respiratory symptoms and conditions such as a chronic cough, shortness of breath, lung inflammation, fibrosis, pulmonary vascular disease, chest tightness, acute myocarditis, heart failure, protracted loss or change of smell and taste, depression, anxiety and cognitive difficulties, inflammatory disease, gastrointestinal disturbances with diarrhea, continuing headaches, fatigue, weakness and sleeplessness, liver and kidney dysfunction, clotting disorders and thrombosis, lymphadenopathy, and even rashes. For more information, listen to The Osterholm Update: COVID-19, Episode 24: Long-Haulers (20:00).
Many of the long-haulers or those with persistent symptoms after COVID-19 infection are young, healthy people. This is not a problem limited to people who are high-risk, older, or faced with severe illness or were hospitalized. For more information, listen to The Osterholm Update: COVID-19, Episode 24: Long-Haulers (30:50).
There is insufficient evidence to know whether convalescent plasma is an effective therapy for severe COVID-19 infections. A National Institutes of Health panel summarized, “There are currently no data from well-controlled, adequately powered randomized clinical trials that demonstrate the efficacy and safety of convalescent plasma for the treatment of COVID-19.” For more information, listen to The Osterholm Update: COVID-19, Episode 21: Crazy Days (31:00) and see "The COVID-19 Treatment Guidelines Panel’s Statement on the Emergency Use Authorization of Convalescent Plasma for the Treatment of COVID-19."
Intensive care unit (ICU) medicine has made great strides in treating people with serious cases of COVID-19. The case mortality has reduced because of the efforts of these front-line medical workers to learn about how to optimally care for people in the ICU. For more information, listen to The Osterholm Update: COVID-19, Episode 25: Ripple Effects (9:00).
To have in-person learning be as safe as possible, schools need guidance based on aerosol science and the knowledge of the current dominant variant. This is not being done. A three-foot distance between students is not based on science and is not enough to reduce risks. It does not take 15 minutes to transmit the Delta variant. Data suggest Delta is transmitted within seconds to minutes. CDC needs to issue guidance based on science and educate schools on how to implement guidance meaningfully. For more information, listen to The Osterholm Update: COVID-19, Episode 66: Thank You, Dr. Jena (50:00).
Reducing risks for in-person learning requires a multi-layered approach. Masks are a tool, but they are not alone sufficient. Reducing crowding and increasing distance helps. The key to a safe environment is ventilation—moving air in and out of the room. All rooms should have at least 5 to 6 air exchanges per hour. A HEPA portable air filter or something similar could be helpful. Far and away, vaccination is our best tool. For more information, listen to The Osterholm Update: COVID-19, Episode 66: Thank You, Dr. Jena (50:00).
To focus on masking alone is missing an opportunity to protect our children. Respiratory protection should be the real focus for schools and communities. Masks or cloth face coverings offer little protection if they are worn below the nose, are too loose, or are made of very thin material. The use of N95 respirators or KN95 approved respirators could have a dramatic impact in keeping people safe. Now we have even KN95 respirators available for children. For more information, listen to The Osterholm Update: COVID-19, Episode 62: Untangling the Data (30:00).
Youth sports have repeatedly been shown to be a high risk for transmission. There have been cases of parents foregoing testing of sick children and allowing them to participate in practices, games, and tournaments, which have caused documented spread of COVID-19. Sports leagues, athletes, and parents should follow the public health guidance that is designed to protect them. Circumventing guidance hurts our communities. For more information, listen to The Osterholm Update: COVID-19, Episode 51: A Balancing Act (30:45) and Osterholm Update Live (March 23, 2021).
The American College of Obstetricians and Gynecologists (ACOG) and the Society for Maternal-Fetal Medicine (SMFM) recommend COVID-19 vaccination for pregnant women. ACOG and SMFM state that "Data have shown that COVID-19 infection puts pregnant people at increased risk of severe complications and even death." It goes on to say that "ACOG is recommending vaccination of pregnant individuals because we have evidence of the safe and effective use of the vaccine during pregnancy from many tens of thousands of reporting individuals....Pregnant individuals should feel confident that choosing COVID-19 vaccination not only protects them but also protects their families and communities."
It is a good idea for pregnant women and their families make maximal efforts to reduce potential COVID-19 exposure leading up to the due date. Doing so will allow you to have a much different experience than if you test positive for COVID-19 at or just before delivery. This is not so much a challenge in terms of the health effects of COVID-19 at delivery as to minimize the disruption of the important bonding and special time with your baby. For more information, listen to the Osterholm Update: COVID-19, Episode 22: Pregnancy in a Pandemic (39:15) and The Osterholm Update: COVID-19, Episode 25: Ripple Effects (26:30).
There is little evidence of additional risk to an infant of receiving breast milk from a COVID-19 positive mother. A COVID-19-infected mother can still breastfeed, but she should practice good hand hygiene and masking. For more information, listen to the Osterholm Update: COVID-19, Episode 22: Pregnancy in a Pandemic (39:00).
Access to healthcare and prenatal care is critical, but major racial and ethnic disparities need to be addressed. The pandemic is highlighting these disparities. For more information, listen to The Osterholm Update: COVID-19, Episode 25: Ripple Effects (25:00).