7-day quarantine may work for some COVID household contacts

Interim study results published late last week in Morbidity and Mortality Weekly Report (MMWR) found that only 19% of people exposed to a COVID-19 patient in their home who had no symptoms nor a positive test result in the first 7 days of the patient's illness later tested positive—lending support for recently changed Centers for Disease Control and Prevention (CDC) guidelines.

To shorten quarantine and improve compliance, a month ago the CDC revised its guidance and now recommends either 10 days of quarantine with no COVID-19 test or 7 days with a negative test result. But noting the risk of viral spread from people who develop symptoms or become infectious toward the end of the initially recommended 14-day quarantine, the researchers sought to quantify that risk.

In the ongoing CDC-supported study, 185 household members of 105 COVID-19 patients at Vanderbilt University Medical Center and Marshfield Clinic Research Institute completed a symptom diary and provided respiratory specimens for 14 days over April to September 2020.

Of 185 contacts, 109 (59%) tested positive during the study period, with 83 of the test results (76%) yielding positive results within 7 days, and 94 (86%) being positive within 10 days after the index patient became ill.

Contacts with negative COVID-19 test results and no symptoms in the first 7 days had an 81% chance of continuing to have no symptoms or test positive through day 14. Those odds increased to 93% for those without symptoms or positive test results in the first 10 days.

After excluding 22 households that may have had more than one index patient and 10 infected contacts who may have contracted the virus outside the home, the conditional probability that the contacts would remain uninfected in the first 14 days was 95% if they were asymptomatic and tested negative through day 10.

The researchers said that while a 14-day quarantine is the best strategy to reduce community coronavirus transmission, access to a sensitive COVID-19 test after a 7-day quarantine could identify infected household contacts and allow a shorter quarantine for those who remain asymptomatic and continue to test negative.

"A shorter quarantine after household exposure to COVID-19 might be easier to adhere to but poses some risk for onward transmission," the authors concluded. "Persons released from quarantine before 14 days should continue to avoid close contact and wear masks when around others until 14 days after their last exposure."
Jan 1 MMWR study
Dec 2, 2020, CIDRAP News story "CDC shortens COVID quarantine, adds holiday travel advice"

Study shows nations with women leaders not faring better in pandemic

Despite popular memes and media reports, countries with women leaders did not fare significantly better during the first several months of the COVID-19 pandemic than countries led by men, according to a study published late last week in PLOS One.

Though New Zealand, Taiwan, Iceland, Denmark, Finland, and Germany—among other countries—have been lauded for their response to the novel coronavirus, analysis of fatality data shows deaths are not significantly lower in these countries compared with those led by men.

The study authors looked at fatality data from 175 countries, 16 of which have female leaders, and ranked the pandemic through a system that looked at the day of the first reported case, the day of the first reported death, and the first day that the number of deaths was greater than 1 per million to compute deaths per capita 30, 60, 90, and 120 days after the start of the pandemic in each country.

There were no significant differences in fatality data between the two types of nations, and the authors instead said the perception that women were better leaders during the pandemic reflected a political double bind of female leaders needing to be both stereotypically masculine and feminine. Moreover, nations that elect female leaders may do so because the population has increased trust in government, which could ultimately lead to more effective pandemic response.

"The perspective that women have been better leaders during the pandemic is rooted in selection bias, based on the selective reporting of cases where women-led countries have succeeded in pandemic management," the study authors said. "These reports fail to acknowledge men-led countries that have done similarly well, while instead emphasizing carefully selected cases where men have not performed well."
Dec 31 PLOS One study

Allergists offer guidance on COVID-19 vaccines for those with allergies

A review published last week in the Journal of Allergy and Clinical Immunology: In Practice provides an outline of what is known about immediate allergic reactions associated with mRNA-based COVID-19 vaccines and offers guidelines on how patients with potential reactions should be managed.

The review, written by a team of US allergists, notes that despite some early reports of severe allergic reactions to the Pfizer-BioNTech vaccine, safety data from the phase 3 trials of both the Pfizer-BioNTech and Moderna vaccines are strong, and to date there have only been 12 reported allergic reactions to the vaccines across more than 2 million administered doses. But they recommend that those with a history of anaphylaxis to an injectable drug or vaccine containing polyethylene glycol or polysorbate speak with their allergists before being vaccinated.

To ensure that the vaccines are administered as quickly as possible and that patients with a prior allergy history receive the vaccines safely, the authors recommend a risk-stratification protocol that allows for the rapid assessment of patients with concerning anaphylaxis histories. They also recommend that vaccination clinic staff have education around anaphylaxis treatment guidelines, that allergists provide support to vaccination programs to ensure appropriate treatment and follow-up for patients who have reactions after their first shot, and that patients with a possible allergic reaction after the first shot be prioritized for further testing and support before their second shot.

"As allergists, we want to encourage vaccination by reassuring the public that both FDA-approved COVID-19 vaccines are safe," lead author Aleena Banerji, MD, of Massachusetts General Hospital (MGH) said in a hospital press release. "Our guidelines are built upon the recommendations of U.S. regulatory agencies and provide clear steps to the medical community on how to safely administer both doses of the vaccine in individuals with allergic histories."

Following reports that two UK recipients of the Pfizer-BioNTech vaccine experienced severe allergic reactions within 48 hours of receiving their first shot, the Food and Drug Administration recommended that both the Moderna and Pfizer-BioNTech vaccines not be given to individuals with a known history of allergic reactions to any components of the vaccine. In addition, the CDC advised that all patients be observed for 15 minutes post-vaccination by staff who can identify and manage such reactions. 
Dec 31 J Allergy Clin Immunol Pract abstract
Dec 31 MGH news release