It’s also not clear how long the protection of the first dose lasts without the surge of a second dose, said Dr. Fauci during a press conference at the White House in April.
April 29, 2021, 4:55 p.m. ET
“We were and still are concerned that if you look at the level of protection after a dose, you can say it’s 80 percent, but it’s a little weak 80 percent,” said Dr. Fauci. He said there was concern that more contagious variants that continue to spread around the globe might partially dodge after just one dose of vaccine-induced antibodies. “You’re in a weak zone if you don’t get the full effect of two doses,” he said.
Breakthrough infections after vaccination, while rare, do occur. A recent study of 250 people in Israel who were infected with the Pfizer vaccine after partial vaccination – between two weeks after the first dose and one week after the second dose – showed that they infected disproportionately with B.1.1.7 variant were first identified in Great Britain. The same study found that a group of 149 people infected after the second dose of vaccine developed eight infections with B.1.351 (the variant first identified in South Africa) between the seventh and 13th day after the second dose. No breakthrough infections with the South African variant were observed 14 days after the second dose. Although it was a small sample, the result suggested that full vaccination would provide more protection against the variants, said Adi Stern, the study’s lead author, a professor at Tel Aviv University’s Shmunis School of Biomedicine and Cancer Research .
Another study showing the benefits of full vaccination looked at a group of 91,134 patients previously seen by doctors at the Houston Methodist Hospital system and followed them between December and April. Most were not vaccinated, but 4.5 percent were partially immunized and 25.4 percent were fully immunized. There were 225 deaths from Covid-19 in the group and 219 (97 percent) were among the unvaccinated. However, five deaths (2.2 percent) occurred in the partially immunized. Only one person (0.004 percent) died in the fully immunized group. In this study, full vaccination was protected 96 times from hospitalization and 98.7 percent from death from Covid-19. However, the partially vaccinated were only 77 percent protected from hospitalization and 64 percent from fatal Covid-19.
The study’s lead author, Saad B. Omer, director of the Yale Institute for Global Health, said he started the research with a “neutral” view of the benefits of two doses over a single dose. But he is now convinced that the benefits of a second dose matter.
“Given the data from our study and other evidence, it doesn’t make sense for people to skip their second dose,” said Dr. Omer. “When it comes to preventing death from vaccines, the jar is 64 percent full, but wouldn’t you rather have it almost 100 percent full for a result as drastic and irreversible as death?”
Aside from the obvious health risks, skipping the second dose can also make your life more complicated if you’re traveling or visiting facilities that require proof of vaccination. “You are not considered fully vaccinated,” said Dr. Brownstein. “It can have an impact on getting back to normal. If your vaccination record or card does not show full status, there may be certain things you cannot do. You may not be able to get on a plane. “