The biggest concern about B.1.1.7 is that it is highly contagious and spreads rapidly among the non-vaccinated, potentially overwhelming hospitals in areas where cases are on the rise.
Do the vaccines work against B.1.1.7?
All major vaccines used – Pfizer-BioNTech, Moderna, Johnson & Johnson, AstraZeneca, Sputnik and Novavax – have been shown to be effective against B.1.1.7. We know this from various studies and indicators. First, scientists used the blood of vaccinated patients to study how well vaccine bodies bind to a variant in a test tube. The vaccinations all performed relatively well against B.1.1.7. There are also clinical trial data, especially from Johnson & Johnson and AstraZeneca (which is the most widely used vaccine in the world), showing that it is very effective in preventing infection and serious diseases in areas where B.1.1.7 is circulating. And in Israel, where 80 percent of eligible populations are vaccinated, for example (all with the Pfizer shot), the number of cases is declining, even as schools, restaurants and workplaces are opened, indicating that vaccines are getting new infections under pressure. , including those caused by variants.
If the vaccines work, why do I keep hearing about ‘breakthrough’ cases?
No vaccine is infallible, and although the Covid vaccines are very protective, people who are vaccinated are still infected. But breakthrough cases of vaccinations are very rare, even though the variants are provoking a surge in the number of cases. And the vaccines clearly prevent serious illnesses and hospitalization in the few vaccinated patients who do become infected.
So, what is the risk of becoming infected after vaccination? No one knows for sure, but we have some clues. During the Moderna trial, for example, only 11 patients out of 15,210 vaccinated were infected. Both Pfizer and Moderna are now conducting more detailed studies of breakthrough cases among participants in vaccinated trials, and the data should be released soon.
Two real studies of vaccinated health workers, who have a much higher risk of exposure to viruses than the rest of us, offers hopeful signs. One study found that only four out of 8,121 employees who were fully vaccinated at the University of Texas’ Southwestern Medical Center in Dallas became infected. The other found that only seven of the 14,990 workers at UC San Diego Health and the David Geffen School of Medicine at the University of California, Los Angeles, tested positive for two or more weeks after taking a second dose of Pfizer-BioNTech or Modern received. vaccines. Both reports have been published in the New England Journal of Medicine, and this is a sign that even through cases that have increased in the United States, breakthrough cases have been uncommon, even among individuals who have often been exposed to sick patients. Most importantly, patients infected after vaccination had mild symptoms. Some people had no symptoms at all, and were only discovered through studies or as part of their unrelated medical care.
Researchers are still investigating whether the variants could eventually increase the number of breakthrough cases, or that antibodies to vaccines would begin to decline over time. So far, data from Moderna show that the vaccine is still 90 percent effective after at least six months. Pfizer reported similar results.
A recent study among 149 people in Israel who became infected after vaccination with the Pfizer vaccine suggested that a variant first identified in South Africa was more likely to cause breakthrough infections. However, these eight infections occurred between days seven and 13 after the second dose. “We did not see any South African variant 14 days after the second dose,” said Adi Stern, senior author of the study, a professor at the Shmunis School of Biomedicine and Cancer Research, Tel Aviv University. ‘It was a small sample size, but it is quite possible that the protection level may rise two weeks after the second dose and could completely block the South African variant. This gives us more room for optimism. ”