Previous COVID-19 associated with greater post-vaccination antibodies
After vaccination with an mRNA-based COVID-19 shot, antibody levels for immunoglobulin G (IgG) were higher in the short term in healthcare workers (HCWs) who had previous COVID-19 infections than those who had never had the disease, according to a research letter published yesterday in JAMA.
The authors recruited their pool of 59 HCWs from a previous serosurvey at the University of Maryland Medical Center, dividing the cohort into three groups: SARS-CoV-2 IgG-antibody negative (17 HCWs), IgG-positive with asymptomatic COVID (16), and IgG-positive with symptomatic COVID (26). HCWs received the first dose of either the Pfizer/BioNTech vaccine or the Moderna vaccine, and blood was drawn 0, 7, and 14 days post-vaccination in December 2020 and January 2021.
Those who did not have COVID had median reciprocal half-maximal binding titers lower than 50 on days 0 and 7 post-vaccination, followed by a median of 924 on day 14, with higher numbers indicating higher antibody levels. Previously infected but asymptomatic HCWS, on the other hand, had titers of 208, 29,364, and 34,033 at days 0, 7, and 14, respectively, while those previously infected and asymptomatic had titers of 302, 32,301, and 35,460, respectively.
“Given the ongoing worldwide vaccine shortages, the results inform suggestions for a single-dose vaccination strategy for those with prior COVID-19 or placing them lower on the vaccination priority list,” the researchers write.
Mar 1 JAMA research letter
Most moms say yes to COVID vaccine for themselves, kids, survey says
In a survey of almost 18,000 pregnant women and mothers of children younger than 18, most would receive a COVID-19 vaccine and vaccinate their children, according to a European Journal of Epidemiology study published yesterday. Across 16 countries, vaccine acceptance was highest in India, the Philippines, and Latin America, and the lowest was in Russia, the United States, and Australia.
Responses were submitted from Oct 28 to Nov 18, 2020. Almost half of respondents were from the United States (4,014, 23.0%), the United Kingdom (2,702, 15.1%), or India (1,639, 9.2%) while the three least-represented countries (Chile, Peru, New Zealand) accounted for under 6%.
A little over half of pregnant women (52.0%), 73.3% of non-pregnant women, and 69.2% of their children would get vaccinated by a safe, free vaccine with 90% effectiveness, the survey reports. The most influential acceptance factors include confidence in the vaccine’s safety and effectiveness, concern about COVID-19, and attitudes toward routine vaccines. Reluctance was driven by a lack of data in these target populations and concern over politicized agendas.
Overall, 53.0% of women were confident that a nationally approved COVID-19 vaccine would be safe, and 60.4% thought it would be effective.
Acceptance varied greatly by country. For instance, 90% of non-pregnant women in India, Brazil, and Mexico would get the vaccine, versus less than 56% in Australia, the United States, and Russia. “Women’s risk perception of COVID-19 in the US and Russia, two countries, was comparable to that in low incidence countries (i.e. Australia and New Zealand), potentially suggesting a phenomenon of COVID-19 denial,” the researchers write. “These results underscore that a high burden of disease alone may not provide sufficient motivation.”
“The perceived threat of COVID-19, level of trust in public health agencies, and existing pre-COVID 19 vaccine attitudes play key roles shaping vaccine acceptance and confidence. Vaccination campaigns should be tailored to alleviate these specific concerns,” said senior author Julia Wu, ScD, in a Harvard University press release.
Mar 1 Eur J Epidemiol study
Mar 1 Harvard press release