Latest Peer-Reviewed Study Underlines Benefits of Second COVID Booster for Older People COVID-19 Science 18/04/2022 • Maayan Hoffman Share this:Click to share on Twitter (Opens in new window)Click to share on LinkedIn (Opens in new window)Click to share on Facebook (Opens in new window)Click to print (Opens in new window) The latest study on the effectiveness of a second COVID-19 booster, published last week in the New England Journal of Medicine, has shown that within a period of two weeks to one month after receiving the jab, recipients’ infection rates dropped by one-half and severe cases and deaths by three-quarters. The study, conducted by Israel’s Clalit Research Institute in collaboration with researchers at Harvard University in Boston, is also one of the largest studies of the fourth jab to date – analysing data of more than 364,244 individuals -182,122 who received the second booster and the same number who did not. The study also was conducted between January 3 and February 18, during the height of Israel’s Omicron wave – pointing to the continued effectiveness of at least the Pfizer mRNA COVID vaccine against that new, and more infectious variant. “The results of the study can help each person make an informed decision about the need for a vaccine according to personal risk,” said Prof. Ran Balicer, Chief Innovation Officer for Clalit Health Services. “Currently, one of the main reasons for hesitation regarding receiving the fourth vaccine dose is a lack of information regarding its effectiveness,” added Prof. Ben Rice, head of a predictive medicine group at Boston’s Children Hospital and Harvard Medical School. “The careful epidemiological research presented before us provides reliable information regarding the effects of the vaccine.” According to the results, those who received the second booster dose experienced a 52% reduction in all infections; a 61% reduction in symptomatic infection; 72% reduction in hospitalizations; a 64% reduction in severe disease; and a 76% reduction in deaths compared to those who had only been vaccinated with the third dose (first booster), at least four months earlier. “A fourth dose of the BNT162b2 vaccine was effective in reducing the short-term risk of Covid-19–related outcomes among persons who had received a third dose at least 4 months earlier,” the study concluded. Western countries push fourth dose for most vulnerable A second booster is equivalent to the fourth shot for anyone who took a Pfizer or Moderna mRNA vaccine regimen. For those who received Johnson & Johnson, it means the third shot. Most countries recommend it four months or more after receiving the first booster. In January, Israel became one of the first countries in the world to recommend a second booster for people over the age of 50 and immunosuppressed individuals. Since then, a handful of other countries – mostly in the Western world – have followed suit. In March 2022, the US Food and Drug Administration authorised a second shot for its elderly (over 50) and vulnerable populations, which was soon after endorsed by the Centers for Disease Control and Prevention. Germany has approved the fourth dose for people over the age of 60 and the United Kingdom recently advised the shot for people over the age of 75. The European Centre for Disease Prevention and Control (ECDC) and European Medicine Agency’s COVID-19 task force said earlier this month that while it is “too early to consider using the fourth dose of mRNA COVID-19 vaccines in the general population,” they recommend the fourth dose for adults over 80 “after reviewing data on the higher risk of severe COVID-19 in this age group and the protection provided by a fourth dose.” The ECDC and EMA also noted that there is ”no clear evidence in the EU that vaccine protection against severe disease is waning substantially in adults with normal immune systems aged 60 to 79 years and thus no clear evidence to support the immediate use of a fourth dose.” However, they said that a re-vaccination campaign could start as early as the fall. “So far, no safety concerns have emerged from the studies on additional boosters,” they said. Earlier studies show similar results The Clalit study follows a handful of other reports on the fourth shot, all conducted in Israel, most of which have been peer-reviewed. A study published earlier this month, also in the NEJM, looked at the rate of infection and severe illness in more than a million Israelis over the age of 60 who received a fourth dose. It found that the rate of COVID-19 infection was initially two times lower among those getting a second booster, than among those who had only received a third dose. Protection against infection, per se, appear to wane quickly, that study found. while protection against severe illness appeared more sustained. The new study, carried out within a longer time frame, reinforces those findings. “Rates of confirmed SARS-CoV-2 infection and severe Covid-19 were lower after a fourth dose of BNT162b2 vaccine than after only three doses,” the study using Israeli Health Ministry data concluded. “Protection against confirmed infection appeared short-lived, whereas protection against severe illness did not wane during the study period.” Fourth COVID Vaccine Jab Provides Little Extra Protection to Healthy Individuals – NEJM Fewer benefits for younger individuals A separate study by researchers from Sheba Medical Center at Tel Hashomer, published only a few weeks earlier, focused on healthy healthcare workers. Significantly, that study, which also assessed the effectiveness of the fourth shot, found that it provides ““little protection, if any, from infection by COVID-19 among vaccinated young and healthy individuals in comparison to those vaccinated with only a third dose,” the lead researcher said. That study included approximately 600 volunteers, among them 270 who received a fourth shot of either the Moderna or Pfizer vaccine. All of the volunteers had received three shots of the Pfizer vaccine prior to the trial. Finally, a non-peer reviewed retrospective cohort study – this one also published in collaboration with Clalit Health Services – was published at the end of March. Of 563,465 members of the fund, 328,597 (58%) received a second-booster dose during the 40-day study period. “Death due to COVID-19 occurred in 92 second-booster recipients and in 232 participants who received one booster dose,” the authors reported, translating to a 78% reduction in death compared to those who only received one booster. “The main conclusion is that the second booster [fourth shot] is lifesaving,” Dr Ronen Arbel, Health Outcomes Researcher at Clalit Health Services and Sapir College, told Health Policy Watch. Image Credits: Clalit Health Fund . 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