Pfizer-BioNTech vaccine (second Covid-19 booster dose): technology, variants, efficacy

The European Medicines Agency (EMA) could approve Pfizer-BioNTech’s new Covid vaccine as early as the fall. This Monday August 15, the CEO of Pfizer, Albert Bourla, announced that he had tested positive for Covid-19, despite four doses. What is the real effectiveness of this new injection?

What technology does the new Pfizer-BioNTech vaccine use?

Like previous injections, the new vaccine against Covid-19 from biotech Pfizer-BioNTech is based on the messenger RNA technology.

It is made from two strains of the virus: the original strain and the Omicron variant, initially the BA.1 variant, now in the minority compared to the BA.4/5 variants, then another from of this last variant.

Pfizer-BioNTech booster dose: how effective is it?

According to a press release published by Pfizer on June 25, this new booster dose has resulted in “significantly higher neutralizing antibody responses against Omicron BA.1″ than the one currently in use. However, its impact is much less on the BA.5 variant – now more than 93% majority on French territory – with antibody levels three times lower.

This is why the American federal drug agency (FDA) asked the manufacturers of messenger RNA vaccines to develop other versions of boosters adapted to BA.5 and BA.4, in order to gain in performance.

Request to which Pfizer immediately reacted, launching new trials. “Omicron has new evolving sublines that have outperformed BA.1 and show a tendency to increase immune evasion potential. We will therefore remain vigilant and stand ready to rapidly adapt our Omicron-adapted vaccine candidates to emerging sublines if epidemiological and laboratory data suggest so.”the statement said.

Where is the vaccine?

On July 19, Pfizer and its partner BioNTech announced that they had transmitted their data (concerning the vaccine effective against BA.1) to the European Medicines Agency (EMA). The latter declared on Wednesday August 10 want to approve an anti-Covid vaccine in the fall targeting two subvariants of the Omicron strain.

A new vaccine effective against BA.4/5 is also in progress. “EMA expects to receive an application for the tailored BA.4/5 vaccine developed by Pfizer/BioNTech, which will be assessed for potential rapid approval in the fall.”said an EMA spokesperson.

An approval that arrives”soon after” that expected from two other vaccines, including that of rival Moderna.

Does the Pfizer-BioNTech vaccine have side effects?

According to Pfizer’s statement, “fainting may occur after receiving injectable vaccines, including the Pfizer-BioNTech vaccine. Sometimes people who pass out can fall or hurt themselves. For this reason, your vaccinator may ask the vaccinated person to sit or lie down for 15 minutes after receiving the vaccine.

Other side effects remain similar to previous doses and may include in particular:

  • Skin rash and itching;
  • Pain and swelling at the injection site;
  • Fatigue;
  • Headaches ;
  • Nausea or vomiting;
  • A feeling of discomfort;
  • Swollen lymph nodes;
  • A decrease in appetite;
  • Diarrhea.


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