As new data begins to demonstrate the waning effectiveness of COVID vaccines over time, health chiefs in Cayman are contemplating if and when booster shots will be required.
Studies in Israel and the UK have shown that the protection conferred by the BioNTech/Pfizer two-shot vaccine — administered to around 70% of Cayman’s population — appears to fade over time.
In Israel, health officials recorded declining antibody levels in vaccinated patients, combined with a surge in “breakthrough infections”.
People who had the jab in the early days of the country’s national vaccination programme were the worst impacted.
An Oxford university study published on Thursday found that the efficacy of the Pfizer vaccine against symptomatic infection almost halved after four months.
While protection against hospitalisation and death remains relatively high, the chances of symptomatic infection increased with time from the initial jab.
Pfizer has acknowledged the data and supports a recommendation for a third dose between 6 and 12 months after getting fully vaccinated.
Cayman began its vaccination programme in January. If the data is correct, those that were inoculated in the early part of the year — including the elderly, vulnerable and health workers — would be most susceptible to breakthrough infections.
Cayman’s Chief Medical Officer Dr. John Lee said he was following the information coming out of the UK and Israel very closely.
He said UK health officials are awaiting the results of a COVID-19 vaccine booster study, expected in the next couple of weeks.
“This is likely to give us information of timings of boosters and the combinations of vaccines that are likely to produce the best results.”
He acknowledged that some who had been vaccinated early in Cayman may be keen to get a third dose — particularly if they have travel plans.
“Until such time as we have the details of the programmes, and how best to manage boosters, I would ask the public to remain patient,” he said.
“The UK has plenty of vaccine stocks which they will no doubt use wisely to protect those who are in need, as they have done since the inception of the programme.”
UK Health Minister Sajid Javid has confirmed that 35 million additional doses of the Pfizer vaccine have been ordered and expressed confidence that a booster programme will begin in the UK in September.
Dr. Lee added, “The Governor has repeatedly reassured the public that should the UK roll out a booster programme, then UK Overseas Territories would receive sufficient vaccine doses to mirror that programme as part of the UK’s ongoing support.”
He said chief medical officers in the overseas territories, including himself, had been given the same assurances during weekly conference calls with Public Health England.
He cautioned, however, that there are still many people in Cayman who are yet to have their first jab.
“I really do hope that those who have not yet been vaccinated come forward. If we end up wasting some of the supply we have been given, which expires at the end of October, the UK Government may find it difficult to prioritise booster shots for us over demands coming from within the UK and other Overseas Territories.”