Credit ACIP/CDC
#16,239
This past week has provided even more evidence of the waning protection - over a period of months - from the initial 2-dose mRNA COVID vaccine. While still pretty effective in preventing serious illness, hospitalization, and deaths - milder breakthrough infections become more common as months pass, particularly among the elderly and immunocompromised.
This Israeli study, published on Oct 6th, in the NEJM.
Waning Immune Humoral Response to BNT162b2 Covid-19 Vaccine over 6 Months
Einav G. Levin, M.D.,Yaniv Lustig, Ph.D.,Carmit Cohen, Ph.D.,Ronen Fluss, M.Sc.,Victoria Indenbaum, Ph.D.,Sharon Amit, M.D.,Ram Doolman, Ph.D.,Keren Asraf, Ph.D.,Ella Mendelson, Ph.D., Arnona Ziv, M.Sc.,Carmit Rubin, M.Sc.,Laurence Freedman, Ph.D.,et al.
CONCLUSIONS
Six months after receipt of the second dose of the BNT162b2 vaccine, humoral response was substantially decreased, especially among men, among persons 65 years of age or older, and among persons with immunosuppression.
Israel was the first to offer `booster shots' starting in late July, and last week made a 3rd shot a requirement after 6 months to get their coveted `green pass' that allows access to restaurants, gyms and many other public venues.
While their policies are less aggressive, the United States, the UK, and Denmark have all permitted some segments of their population - based on the timing and type of their original vaccination, and individual risk factors - to get a booster shots.
Next week the FDA advisory committee will meet to discuss the use of booster doses of the Moderna COVID-19 Vaccine and the Janssen COVID-19 Vaccine in the United States. At the same time, the World Health Organization is lobbying strongly against the use of booster shots until more first vaccine doses can be delivered to underserved nations.
While the world debates the necessity for COVID booster shots - and who should be eligible to get them them (and when) - we are starting to get real-world evidence on the impact they are having in countries that have embraced their use.
In today's example, the Statens Serum Institut reports a marked decrease in COVID infections among nursing home residents following the roll-out of the booster shot. This, even while the rate of cases in the general population has risen slightly over the past few weeks.
Fewer elderly people in nursing homes are infected with covid-19
In recent weeks, there has been a marked decrease in the number of nursing home residents who test positive for covid-19.
Last edited October 8, 2021
While the number of covid-19 cases is currently rising nationwide, the situation looks quite different at the country's nursing homes. Here, there has been a marked decrease in the number of nursing home residents who tested positive for covid-19.
From week 38 to 39, the incidence nationwide increased from 43 to 52 covid-19 cases per week. 100,000 inhabitants. This is shown by the latest figures from the Statens Serum Institut (SSI).
From 18 to 4 cases
In nursing homes, however, the number of covid-19-infected residents dropped from 18 to just 4 new cases from week 38 to 39. That is a massive drop of almost 78% in just one week.
And that is a decrease of over 90% compared to week 36, when 45 new cases were detected.
At the same time, the number of nursing homes where covid-19 has been detected in one or more of the residents has fallen from 18 in week 36 to 4 nursing homes in week 39.
Suggests that the booster vaccine works
The marked decline coincides with the revaccination of nursing home residents with a third dose of covid-19 in week 36.
“Since week 36, the vast majority of nursing home residents have fortunately accepted the offer of a third plug. And if you look at the positive numbers, it indicates that the booster vaccines work ", says SSI's professional director Tyra Grove Krause.
The big unknown is how long the beneficial effects of a booster shot will last. Will its protection fade over 6 months as we've seen with the initial two-dose regimen? Or will it `complete' the initial course of for the COVID vaccine, and provide longer lasting protection?
We likely won't know those answers until next spring. But in the meantime - particularly for those at greater risk of severe illness from COVID - another six months of protection probably doesn't sound so bad.
