WHO recommends new COVID-19 shots should target only XBB variants
A World Health Organization (WHO) advisory group on Thursday recommended that this year's COVID-19 booster shots be updated to target one of the currently dominant XBB variants.
New formulations should aim to produce antibody responses to the XBB.1.5 or XBB.1.16 variants, the advisory group said, adding that other formulations or platforms that achieve neutralizing antibody responses against XBB lineages could also be considered.
The group suggested no longer including the original COVID-19 strain in future vaccines, based on data that the original virus no longer circulates in human beings and shots targeting the strain produce "undetectable or very low levels of neutralizing antibodies" against currently circulating variants.
COVID-19 vaccine makers like Pfizer/BioNtech, Moderna Inc and Novavax Inc are already developing versions of their respective vaccines targeting XBB.1.5 and other currently circulating strains.
The U.S. Food and Drug Administration is also set to hold a meeting of outside experts in June to discuss the strain compositions of COVID-19 shots for later this year; vaccine manufacturers will be expected to update their shots once the strains are selected.
The bivalent booster shots developed and distributed last year targeted two different strains - the Omicron variant as well as the original virus.
WHO's advisory group, which recommends if changes are needed to the composition of future COVID-19 shots, said currently approved vaccines should continue to be used in accordance with the agency's recommendations.
In late March, WHO had revised its COVID-19 vaccination recommendations and suggested healthy children and adolescents might not necessarily need a shot, but older and high-risk groups should get a booster between six and 12 months after their last vaccine.
The latest recommendations come about two weeks after WHO ended the global emergency status for COVID-19.
CTVNews.ca Top Stories

NDP to form majority government following historic Manitoba election
Wab Kinew’s New Democratic Party is projected to have enough seats in the Manitoba Legislature to form a majority government, taking the helm after two consecutive terms of a majority Tory regime.
Parks Canada reveals additional details about deadly bear attack in Banff
The couple and dog mauled and killed by a grizzly bear in the backcountry of Banff National Park late last week did everything right, Parks Canada says.
Parents want arrest after son 'deliberately kicked' in neck during Edmonton hockey game
A Junior C hockey player says he is lucky to be alive after his neck was sliced open by a hockey skate last week in an act his parents believe – and the referee ruled – was an intentional kick.
A look back at election day in Manitoba
Manitobans have cast their vote in a historic election. The CTV News Decision Desk has declared an NDP majority win, making NDP Leader and Premier-elect Wab Kinew the first First Nations premier in the province. Take a look at the election night in Manitoba.
Multiple people have been shot on campus of Morgan State University in Baltimore, police say
Multiple people were shot at Morgan State University in Baltimore on Tuesday, according to police, who urged students to take shelter on the campus of the historically Black college.
Canadian condo sales falling amid concerns over interest rate hikes
Amid consistent interest rate hikes and wavering markets, Canadian condo sales are starting to fall in all but two markets in the nation, according to a new report from Re/Max.
McCarthy becomes the first U.S. speaker ever to be ousted from the job in a House vote
U.S. House Speaker Kevin McCarthy was voted out of the job Tuesday in an extraordinary showdown, a first in U.S. history that was forced by a contingent of hard-right conservatives and threw the House and its Republican leadership into chaos.
Train service restored after CN experiences network-wide system failure
Canadian National Railway Co. experienced a network-wide system failure on Tuesday that affected Via, GO and other trains in Ontario. The issue was resolved and service was restored Tuesday night.
Tropical Storm Philippe could impact the Maritimes on Thanksgiving weekend
The Maritimes have been on an extended run of very fair weather the last two weeks while under a persistent ridge of high pressure. Unfortunately, that pattern changes this weekend with the approach of a weather front from the west and a likely post-tropical storm Philippe from the south.