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).
Monitoring COVID-19 case trends during this phase in the pandemic is difficult. Fewer PCR tests are being performed. Lateral flow (or rapid) tests are rarely reported to public health departments. Wastewater sampling isn't standardized. We are left to lagging measures of infection, such as hospitalizations and ICU census. For more information, listen to The Osterholm Update: COVID-19, Episode 101: Class in Complicated Times (21:00) The Osterholm Update: COVID-19, Episode 100: You Can't Stop the Wind (55:00).
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.
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. For a list of the variants of concern and variants of interest, see the WHO website.
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).
Wear a face covering—one 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).
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."
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).
It is not known the extent or timing of waning vaccination protection, but studies suggest that immunity does decrease months after vaccination. Third doses for the mRNA vaccines or second doses for the Johnson & Johnson vaccines, also known as boosters, have been shown to increase protection. Fourth doses are also recommended for people with compromised immune systems. For more information, listen to the Osterholm Update: COVID-19, Episode 76: Vaccines in the World of Delta (32:30) and the Osterholm Update; COVID-19, Episode 91: The Decline of Omicron (29:30).
Preliminary data indicate that, while previous infection with COVID-19 can protect you from COVID reinfection, at least one vaccine dose can offer additional protection. The protection from natural infection is variable, depending on timing, the severity of infection, and underlying health conditions. Current data do not perfectly define the protection from COVID-19 infection and vaccination. For more information, listen to the Osterholm Update: COVID-19, Episode 75: Evolving Science (49:00).
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).
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 four vaccines approved for use in the United States—made by Moderna, Pfizer/BioNTech ("Pfizer," for simplicity), Johnson & Johnson, and Novavax. 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.
A person can receive the COVID-19 vaccine and influenza vaccine at the same visit.
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. For more information, listen to the Osterholm Update: COVID-19, Episode 32: Stop Swapping Air (12:00).
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) and The Osterholm Update: COVID-19, Episode 88: Vaccines, Variants and Long COVID (47:00).
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) and The Osterholm Update: COVID-19, Episode 88: Vaccines, Variants and Long COVID (47:00).
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) and The Osterholm Update: COVID-19, Episode 88: Vaccines, Variants and Long COVID (47:00).
There are three antiviral drugs and several monoclonal antibody treatments available in the US, but the benefits of therapeutics are currently hampered by lack of awareness of eligibility and effectiveness, testing delays, and distribution issues. We need to act now to make effective testing and results available in a timely manner and to connect eligible newly COVID-19 positive patients with these therapeutics. These treatments could reduce COVID-19–associated hospitalizations and deaths if used to the fullest extent possible. For more information, listen to the Osterholm Update: COVID-19, Episode 91: The Decline of Omicron (46:15).
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).
It is a difficult time for people living with a compromised immune system and their loved ones. Here are steps to take to protect yourself: (1) Get a fourth dose of Moderna or Pfizer vaccine or third dose of Johnson & Johnson. (2) Wear high-quality respiratory protection (N95 or KN95) tightly over your nose and mouth without facial hair when in public spaces. (3) Have a plan if any minor symptoms of COVID-19 occur for how to access quality testing and receive therapeutics (drugs) quickly if you test positive for COVID-19. For more information, listen to The Osterholm Update: COVID-19, Episode 94: The Next Normal (52:30).
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 or Omicron variants. Data suggest these variants are 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).
Vaccination is the best tool available to protect schoolchildren and their communities. Pfizer and Moderna COVID-19 vaccination is authorized for all people 6 months or older in the United States. For more information, listen to the Osterholm Update: COVID-19, Episode 76: Vaccines in the World of Delta (51:00).
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).
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).