The UK accepted a Covid-19 vaccine earlier than the US. Here is why.
A patient receives the Pfizer / BioNTech Covid-19 vaccine as UK vaccination roll-out begins Tuesday December 8th at a health center in Cardiff, Wales. Sarah Tilotta / CNN
An advisory committee to the U.S. Food and Drug Administration released an informational document on Tuesday listing data on Pfizer and BioNTech’s vaccine candidate Covid-19 that is being considered for approval for emergency use in the U.S. this week.
The document confirms that the vaccine’s effectiveness against Covid-19 was 95% and appeared at least seven days after the second dose – an effectiveness that Pfizer had previously reported. The suggested dosing regimen for the vaccine is to give two doses of 30 micrograms 21 days apart.
However, the document also notes that the vaccine, called BNT162b2, appears to offer “some protection” against Covid-19 after just one dose.
The document describes the effectiveness of the Pfizer vaccine in the time between the first and second dose as 52.4%. However, the document states that “the efficacy observed after dose 1 and before dose 2 from a post hoc analysis cannot support the conclusion that a single dose of the vaccine is effective, since the observation time is limited by the fact that most participants received a second dose after three weeks. “
In other words, “The study did not have a single-dose arm to make a fair comparison.”
The document cites the vaccine’s safety profile as “favorable” and states that the most common side effects of the vaccine were injection site reactions, fatigue, headache, muscle pain, chills, joint pain and fever.
Serious side effects occurred in less than 4.6% of participants, were more common after the second dose, and were generally less common in older adults than in younger participants, according to the document. The document adds that swollen lymph nodes may also be related to vaccination.
Overall, “there is currently insufficient data to draw conclusions about the safety of the vaccine in subpopulations such as children under 16, pregnant and breastfeeding individuals, and immunocompromised individuals,” the document said.
A total of six participants died during the studies, and “all deaths represent events that occur at a similar rate in the general population in the age groups in which they occurred.”
The document will be discussed at a meeting on Thursday where the FDA Advisory Committee on Vaccines and Related Biological Products will provide the FDA with recommendations on whether the vaccine is effective in preventing Covid-19 in people aged 16 and older, and on the potential benefits of the vaccine outweigh the risks.
‘The committee will also discuss what additional studies vaccine manufacturers should conduct after the EEA is granted to gather more data on the safety and effectiveness of this vaccine,’ the document reads.