WASHINGTON, March 16, 2022 (BSS/AFP) - Pfizer and BioNTech announced
Tuesday they had formally asked the United States drug regulator for
emergency approval of a second booster shot of their Covid vaccine for people
aged 65 and older.

  The companies said in a press statement that their request is based off two
Israeli studies that show "an additional mRNA booster increases
immunogenicity and lowers rates of confirmed infections and severe illness."

  Most countries' case-levels have significantly declined from record levels
during the Omicron wave, though multiple countries have seen levels plateau
or start to tick up as they lift restrictions, and protection from prior
doses begins to fade.

  The first Israeli study cited by Pfizer and BioNTech showed that "rates of
confirmed infections were 2 times lower and rates of severe illness were 4
times lower among individuals who received an additional booster dose,"
compared to those who only had one.

  The analysis was limited to people 60 years and older who received their
second booster four months after their first.

  The second study -- an analysis of Israeli healthcare workers 18 years and
older -- showed that antibody levels in those who received a second booster
were significantly higher than those who did not.

  "The study also revealed no new safety concerns in individuals who received
an additional booster dose of the vaccine," said the companies.

  Since the initial regimen of the Pfizer-BioNTech vaccine is two doses, a
second booster would be most individuals' fourth jab.

  Recent studies have offered evidence that while a third mRNA vaccine dose
raises antibody levels above those of the initial regimen, a fourth dose only
returns individuals' levels to that same highly-elevated level.

  Several European countries, as well as Israel, have already approved second
boosters for older and immunocompromised populations, who are most at-risk
for severe disease.