(Bloomberg) -- The British government has picked Pfizer Inc. over local drug giants GSK Plc and AstraZeneca Plc to supply millions of doses of its RSV shot to the UK. 

Pfizer was chosen to provide over 3.5 million doses of its Abrysvo vaccine to older adults and more than 1.4 million doses to pregnant mothers to protect their babies in England and Northern Ireland over the next two years, according to a redacted contract published earlier this month. 

The decision is a blow to both GSK, which has a rival vaccine for older adults, as well as AstraZeneca and Sanofi, which have jointly developed a monoclonal antibody that protects infants against RSV. 

In the US, GSK is currently locked in competition with Pfizer to corner the new market to protect against respiratory syncytial virus, a common but sometimes deadly disease that is most dangerous for the very young and the elderly. 

The decision to only adopt a maternal vaccine program, rather than immunize babies, is “a missed opportunity to offer RSV protection to all infants, which would help further alleviate the strain on families and the NHS,” Sanofi said in an emailed statement late Monday. The French drugmaker is “deeply disappointed” by the decision, which it said “is likely to leave many UK infants entering their first RSV season at risk of RSV-related lower respiratory tract disease.”

The contract followed a competitive tender process, a Pfizer spokesperson said. GSK said it was disappointed but confident in the value of its vaccine. 

The vaccine deliveries are due to start in July to protect the elderly and newborn babies before the next cold season. The vaccination campaign will kick off in September, according to a letter from NHS England and the UK Health Security Agency to staff working in the health service published after Bloomberg News reported on the contract award. 

Pfizer’s shot is the only one cleared for both pregnant women — to protect their unborn babies — and the elderly. GSK’s vaccine Arexvy is only approved for older adults. The vaccines will be given to adults aged between 75 and 79, despite being authorized for use in adults aged 60 and over, according to the letter. Women who are at least 28 weeks pregnant on Sept. 1 will also be eligible. 

Both products prevent infection by the virus and keep people out of the hospital. After one season, GSK’s vaccine was more effective at protecting against severe disease at 94.1%, versus Pfizer’s 88.9%. Following a second season, the combined efficacy against severe illness was 78.8% for GSK’s shot and 81.5% for Pfizer’s. The data is not directly comparable as the companies report effectiveness against more severe RSV differently and the follow-up periods differed by a few months.

Government’s Criteria

The Department of Health and Social Care hasn’t said why Pfizer’s tender won in the older adults category, and the agency also didn’t say why it didn’t award a contract for a new monoclonal antibody. The UK government is currently restricted from publishing announcements that could impact any political party during the pre-election period. 

The agency’s criteria takes into account both price and efficacy. In the case of the RSV vaccine, the companies won a set number of points if their product provided protection across two RSV seasons, which they did. On pricing, points were deducted for each extra £1 in cost.

While price details are redacted from the UK tender, the US list price of GSK’s vaccine is $280, and Pfizer’s Abryvso is $295. Drugmakers typically offer the UK significant discounts on their US list prices.

The first vaccines came to the market last year and swiftly showed they would become blockbusters. GSK’s garnered more than £1 billion ($1.3 billion) in sales in 2023, compared with $890 million for Pfizer’s shot.

GSK shares rose 0.6% in London trading on Monday. The stock has gained 11% this year. Meanwhile, Pfizer’s shares advanced 2.2% in New York trading, paring the stock’s year-to-date decline to 1.5%. 

(Updates with details of Sanofi, Astra tender outcome from paragraph one.)

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