US approves fourth Covid vaccine dose for people over 50

Age group has felt brunt of severe illness and deaths from Covid-19

A sign promoting Covid-19 vaccines outside a clinic in Providence, Rhode Island, on March 3. AP

US adults over the age of 50 can be inoculated with a fourth Covid-19 dose from Moderna or Pfizer-BioNTech today if it is more than four months since their last vaccination, US health and regulatory agencies ruled on Tuesday.

The Centres for Disease Control and Prevention says the highly contagious Omicron BA.2 subvariant has become the main variant in the country, and there are concerns that a new surge may come.

“Current evidence suggests some waning of protection over time against serious outcomes from Covid-19 in older and immuno-compromised individuals," said Dr Peter Marks, a director at the Food and Drugs Administration.

"Based on an analysis of emerging data, a second booster dose of either the Pfizer-BioNTech or Moderna Covid-19 vaccine could help increase protection levels for these higher-risk individuals."

Older people have felt the brunt of severe illness and deaths from Covid-19 infections.

US agencies are calling the fourth dose a "second booster" because the definition of "full vaccination" is two doses in the country, despite evidence showing that three best protect against Omicron variants.

At least 75.4 per cent of US adults are fully vaccinated, the CDC says, while 48.2 per cent of eligible fully vaccinated people have received their initial booster dose.

The country is having a seven-day average of more than 26,000 daily coronavirus cases, with experts watching to see if a sharp rise will follow BA.2 surges in European countries.

The FDA and CDC said they would review the need for more doses for all Americans in the future.

"CDC, in collaboration with FDA and our public health partners, will continue to evaluate the need for additional booster doses for all Americans," said Dr Rochelle Walensky, director of the CDC.

US President Joe Biden's administration has been trying to compel US Congress to fund its $22.5 billion pandemic response plan, which finances any vaccine orders that may be needed later.

Health non-profit Kaiser Family Foundation says the US has enough vaccine doses for 70 per cent of the US population over the age of 50 to have a second booster.

Their analysis finds that the country does not have enough doses for 100 per cent of people aged 50 or over to have a fourth dose — or for Americans of all ages, if the CDC and FDA choose to do that this year.

A 6-year-old receives a dose of the Pfizer Covid-19 vaccine at a vaccination clinic in Los Angeles. EPA

Nurses prepare doses of Covid-19 vaccine at a pop-up vaccination clinic in Los Angeles, California. EPA

A product stall filled with free N95 respirator masks, provided by the US Department of Health and Human Services, sits outside the pharmacy at a Jackson, Mississippi, Kroger grocery store. AP

A hospital sitter provides companionship, observation and surveillance to assigned patients at St Mary Medical Centre in Apple Valley, California. Reuters

A 13-year old receives a dose of the Pfizer Covid-19 vaccine at a clinic in Los Angeles. EPA

A sign advises patrons of a Covid-19 restriction while long icicles grow from an awning outside a restaurant in Denver, Colorado. AP

A registered nurse works with a Covid-19 patient inside the infectious disease unit (IDU) at Helen Keller Hospital in Sheffield, Alabama. AP

A person self-tests for Covid-19 at a free drive-through testing site in Whittier, California. AP

Workers wear protective equipment at a Covid-19 testing site in the Boyle Heights section of Los Angeles. AP

Pupils leave a high school in Arlington County, one of several school districts which sued to stop the mask-optional order by Governor Glenn Youngkin, in Arlington, Virginia. Reuters

Protesters rally against Covid-19 vaccine mandates in front of the Lincoln Memorial in Washington. AP

People wearing face masks walk past a business displaying a sign requiring face coverings in Washington. Reuters