COVID vaccine protection wanes within six months – UK researchers

LONDON (Reuters) -Protection against COVID-19 offered by two doses of the Pfizer/BioNTech and the Oxford/AstraZeneca vaccines begins to fade within six months, underscoring the need for booster shots, according to researchers in Britain.

After five to six months, the effectiveness of the Pfizer jab at preventing COVID-19 infection in the month after the second dose fell from 88% to 74%, an analysis of data collected in Britain’s ZOE COVID study showed.

For the AstraZeneca vaccine, effectiveness fell from 77% to 67% after four to five months.

The study was based on data from more than a million app users, comparing self-reported infections in vaccinated participants with cases in an unvaccinated control group.

More data is needed in younger people because participants who had their shots up to six months ago tended to be elderly as that age group was prioritised when the shots were first approved, the study authors said.

ZOE Ltd was founded three years ago to offer customised nutritional advice based on test kits. The company’s ZOE COVID Symptom Study app is a not-for-profit initiative in collaboration with King’s College London and funded by the Department of Health and Social Care.

Under a worst-case future scenario, protection could fall below 50% for older people and healthcare workers by the winter, Tim Spector, ZOE Ltd co-founder and principal investigator for the study, said.

“It’s bringing into focus this need for some action. We can’t just sit by and see the protectiveness slowly waning whilst cases are still high and the chance of infection still high as well,” Spector told BBC television.

Britain and other European nations are planning for a COVID-19 vaccine booster campaign later this year after top vaccine advisers said it might be necessary to give third shots to the elderly and most vulnerable from September.

The U.S. government is preparing to provide third booster doses starting in mid-September to Americans who had their initial course more than eight months ago.

“This is a reminder that we cannot rely on vaccines alone to prevent the spread of COVID,” said Simon Clarke, Associate Professor in Cellular Microbiology at the University of Reading, who was not involved in the study.

He cautioned that the results may have been distorted by the surge in overall cases in Britain in July.

A separate British public health study found last week that protection from either the Pfizer-BioNTech or the AstraZeneca vaccine against the now prevalent Delta variant of the coronavirus weakens within three months.

The Oxford University study found at the time that 90 days after a second shot of the Pfizer or AstraZeneca vaccine, their efficacy in preventing infections had slipped to 75% and 61% respectively. That was down from 85% and 68%, respectively, seen two weeks after a second dose.

PARIS (Reuters) -Lionel Messi said on Wednesday he wanted to power Paris St Germain to their first Champions League trophy, putting the tearful farewell he bade to Barcelona behind him after signing a two-year contract with the deep-pocketed French soccer powerhouse.

Messi joined the star-studded PSG as a free agent after Barcelona, where he begun and always imagined he would play out his career, acknowledged last week they could no longer afford him.

Thousands of PSG fans thronged the side’s Parc des Princes stadium, daring to believe their team would now deliver the Champions League having hoovered up domestic titles since free-spending owners Qatar Sports Investment European arrived in 2011 but always fallen short of European soccer’s top prize.

Messi said he was hungry to add more Champions League titles to the four he won with Barcelona.

“That’s why I am here (to win trophies). It’s an ambitious club,” Messi told a news conference.

After years of failing to get beyond the quarter-finals, PSG finally reached the final in 2020, but lost to Bayern Munich, while last season they went out in the semi-finals.

“My dream is to win another Champions League, and I think this is the ideal place to be to do that,” added Messi, who in a nod to his first squad number in senior football at Barcelona will wear the No. 30 jersey at PSG.

The Argentine conceded he did not know when he would make his debut, having not played since winning the Copa America with his country last month.

“I’m coming back from holiday. I need a bit of a pre-season to get myself going,” he said.

FAIR PLAY RULES

Messi will join former Barca team mate Neymar in Paris.

The Brazilian left Catalonia for the French capital in a world record 222 million euro ($259.94 million) deal in 2017, but never hid his desire to link up with his close friend once again on the pitch.

They will now line up with French Word Cup-winner Kylian Mbappe in a potent front-three attack.

“To play with the likes of Neymar and Mbappe is insane,” Messi continued.

France’s top soccer league has always been perceived as the poorer cousin to top flight leagues in neighbouring England, Germany, Spain and Italy.

PSG’s Qatari money is enabling PSG to compete at their level, though much of the rest of the league is way adrift in terms of resources. In unusual comments praising a club’s transfer dealings, Ligue 1 President Vincent Labrune celebrated Messi’s signing as a big win for French soccer.

“The arrival of Messi will bolster the attractiveness and visibility of our championship across continents,” Labrune said in a statement. He thanked the club’s owners for creating what he called one of sport’s biggest franchises globally.

However, some commentators have asked how PSG could afford to sign Messi within the Financial Fair Play (FFP) regulations of European soccer’s governing body, UEFA.

UEFA’s FFP rules are designed to prevent clubs spending more than they earn. Spain’s La Liga’s own FFP rules are more stringent than UEFA’s, with each club given a salary cap they must adhere to.

“We’re always attentive to Financial Fair Play. It’s the first thing we check with the commercial, financial and legal people before signing someone,” PSG chairman and CEO Nasser Al-Khelaifi told the same news conference.

“MAGICIAN”

Messi held up his new shirt to thousands of fans outside the stadium, waving shyly as they beat drums, released smoke flares and chanted his name.

Local fan Nelson Dross, 17, told Reuters: “Why do I love him? Because he makes us dream. He’s a magician, a genius.”

Messi wept on Sunday as he told Barcelona fans he was leaving his childhood club.

“I’ll always be thankful to Barca and their fans. I went there as a boy, and we had some good and bad times,” he said on Wednesday.

Asked how he would feel if the time came to square up against his old club, he replied: “It would be nice on the one hand to face them in the Champions League, especially with fans, but on the other strange to go back to my home in another team’s shirt – but that’s football.”