Plans to accelerate and expand booster programmes against COVID-19 are being announced across the world as countries seek to counter the threat posed by the new variant of concern, Omicron.

The UK will now offer all adults a booster jab by the end of January the government has announced. Previously, the scheme was restricted to those aged 40 or over and younger people who were vulnerable or exposed to the virus through their work. Now, all adults 18 and over are eligible, with the waiting time after the second dose of the primary vaccine course reduced from six to three months.

The UK government has also announced plans to expand the availability of booster jabs with new hospital hubs and pop-up centres, and by using 1,500 community pharmacies.

“Our best weapon to fight the virus is to get as many jabs in arms as possible,” said UK Secretary of State for Health and Social Care Sajid Javid. “This is a national mission and we all have a role to play – so step up, roll up your sleeves, and get protected when the time comes.”

Across Europe, countries were already expanding their booster roll-outs prior to the arrival of Omicron due to a surge in COVID-19 cases. Germany has expanded booster shots to all adults, while France and Italy have said they would make booster jabs available to all adults, five months after their second dose.

The EU has also announced that, from 10 January 2022, all travellers entering the EU must have either received a booster dose or had their second jab within nine months. Plans are also being formulated for boosters to be recognised in vaccine certificates.

In the US, the Centers for Disease Control and Prevention (CDC) is urging everyone aged 18 years and older to come forward for a booster shot. Health regulators have expanded the eligibility for booster shots to all adults aged 18 and older six months after their initial Pfizer or Moderna vaccine or two months after their Johnson & Johnson shot.

Events are moving quickly after the discovery in November of a new, potentially more infectious variant of SARS-CoV-2, B.1.1.529, now labelled Omicron by the World Health Organization (WHO).

A range of countries reacted with travel bans to the affected areas of southern Africa, including South Africa and Botswana, in an effort to limit its spread. However, cases of Omicron have now been reported in several countries in Europe and Asia, as well as in North America.

In the Netherlands, 61 passengers out of 600 arriving from the region on 26 November tested positive for the virus, 13 of whom are known to have the Omicron variant.
The WHO has warned that travel bans should only be used as part of a ‘risk-based and scientific approach’, while South Africa’s president, Cyril Ramaphosa, has asked for the travel bans to be lifted. However, there is little sign that other countries are heeding this advice. In fact, Japan has taken even stronger action, banning all foreigners from entering the country from 30 November.

Fuelling the emergency measures is the fear that the new variant will ‘escape’ the COVID-19 vaccines due to the wide range of mutations in the new variant. Professor Tulio de Oliveira, director of the Centre for Epidemic Response and Innovation in South Africa, called the “unusual constellation of mutations” a “big jump” for the virus, pointing to the fact that 30 of the 50 new mutations are on the all-important spike protein, the target of most vaccines.

Vaccine maker BioNTech said: “We understand the concern of experts and have immediately initiated investigations on variant B.1.1.529. We expect more data from the laboratory tests in two weeks at the latest. This data will provide more information about whether B.1.1.529 could be an escape variant that may require an adjustment of our vaccine if the variant spreads globally.”

Earlier this year, Pfizer and BioNTech announced that they had made the necessary preparations to adapt their mRNA vaccine to an ‘escape’ variant, such as B.1.1.529 within six weeks.

In the light of the new variant of concern, Omicron, the need for treatments for COVID-19 as well as preventative vaccines is climbing.

The group that advises the Food and Drug Administration (FDA) has voted to recommend Merck/MSD’s antiviral molnupiravir, which means the treatment could be authorised and made available to patients within weeks.

The UK’s Medicines and Healthcare products Regulatory Agency (MHRA) became the first regulatory agency to approve the drug in early November 2020. Merck developed molnupiravir with Ridgeback Biotherapeutics.

“With the continued spread of the virus and the emergence of variants, additional treatments for COVID-19 are urgently needed,” said Dr Dean Y Li, president of Merck Research Laboratories. “That is why we are moving with speed and rigor to pursue authorisations and to accelerate broad global access to this investigational medicine.”

The data behind molnupiravir is from the phase 3 MOVe-OUT clinical trial in non-hospitalised adult patients with mild to moderate COVID-19 who were at high risk of severe disease. The drug significantly reduced hospitalisations and death; 14.1% of patients in the placebo group were hospitalised or died compared to 7.3% of those on molnupiravir, resulting in a 50% reduction in the risk of hospitalisation or death.

However, the vote by the FDA’s advisory group was closer than originally thought with 13 votes in favour and ten against, reflecting the modest reduction in the risk of hospitalisation and death.

The recommendation to the FDA clears the way for a second oral antiviral, Pfizer’s Paxlovid, which is more effective than Merck’s drug.

Pfizer halted its phase 2/3 trial for the antiviral early after an analysis showed that it cut the risk of hospitalisation or death from COVID-19 by nearly 90%.

Paxlovid is a combination of experimental antiviral PF-07321332 and antiretroviral ritonavir, best known as an HIV treatment, which slows the breakdown of PF-07321332 increasing its duration of action.

Oral medications like molnupiravir and Paxlovid are significantly more convenient than the injectable COVID-19 treatments that are currently being used, including Gilead’s Veklury (remdesivir).

With cases of Omicron appearing across the world, it is clear that travel bans will not be enough to prevent the spread of the new SARS-CoV-2 variant of concern.

Attention is turning to the vaccines that most developed countries are relying on to control the COVID-19 pandemic, asking two key questions: will the existing vaccines work against Omicron and, if not, how quickly can manufacturers ‘tweak’ them to boost their efficacy?
Pfizer/BioNTech, Moderna and Johnson & Johnson have all announced that they have begun work on Omicron-specific versions of their existing vaccines.

Stéphane Bancel, CEO of Moderna, caused ripples when he predicted that existing vaccines would be much less effective at tackling Omicron than earlier strains of coronavirus.

“There is no world, I think, where [the effectiveness] is the same level [we] had with Delta,” he said. “[There is] going to be a material drop.”

Politicians and public health experts, however, have struck a more positive note. US President Joe Biden called Omicron “a cause for concern, not a cause for panic”, adding that the government’s medical experts “believe that the vaccines will continue to provide a degree of protection against severe disease”.

Scott Gottlieb, now working at Pfizer but previously commissioner of the US FDA agreed, saying there was “a reasonable degree of confidence in vaccine circles that [with] at least three doses… the patient is going to have fairly good protection against this variant”.

BioNTech CEO Uğur Şahin has been talking about the similarities he sees between tweaked COVID-19 vaccines and the seasonal flu vaccine, suggesting regulatory agencies such as the FDA could use flu as a blueprint.

“We are generating a data set to get a blueprint process approved – to ensure that if a new variant pops up that requires an adaptation of the vaccine because the original vaccine doesn’t work anymore, we can just come up with a variant vaccine, and not do a large clinical trial,” he said.

Gottlieb agreed, saying the FDA was familiar with the mRNA vaccines and that they would seek “immunogenicity data, maybe neutralisation studies” rather than “new outcomes studies”.