At least five fully vaccinated travellers have tested positive for COVID-19, Chief Medical Officer Dr. John Lee has confirmed.
Lee, responding to queries from the Cayman Compass on Thursday, said these positive cases have occurred over a period of around three months. They have involved persons who have been inoculated using different vaccines.
Positive cases in fully vaccinated individuals are rare, but are still possible and have been categorised as COVID-19 breakthrough cases in the US.
It was at Wednesday’s COVID-19 briefing, that Lee shared three of Cayman’s five ‘breakthrough cases’ had received their vaccines at the Health Services Authority.
“We’ve detected five people who have been vaccinated who have tested positive at some point. I am pretty sure the last two or three were on arrival but I cannot promise… I don’t have that figure in my head,” Lee said as he responded to questions at the briefing.
He said apart from the HSA-vaccinated individuals, one was vaccinated with Moderna and two were vaccinated with a Chinese vaccine.
Cayman mainly uses the Pfizer vaccine; only a limited amount of AstraZeneca vaccines have been administered locally.
Lee, in his emailed comment to the Compass, stressed the importance of vaccination.
“We know that vaccines prevent a lot of transmission of SARS-CoV-2 but they do not prevent all of it. The Pfizer-BioNTech vaccine probably prevents in the region of 80% transmission. Please remember that just because we can detect the presence of the virus in someone’s airways, this does not mean that they can definitely spread it – that is a bit of an unknown in any single individual. The vaccines are also not 100% effective. All of this points us to get as many people vaccinated as possible, as it’s the best possible protection,” he said.
Based on recent figures 39,090 persons resident in the Cayman Islands have received a full dose of the COVID-19 vaccine. This equates to approximately 55 per cent of the population.
Cayman’s vaccination programme resumed Thursday after fresh supplies of the Pfizer vaccine were delivered Wednesday afternoon aboard the British Airways flight.
Breakthrough cases under surveillance
The US Centers for Disease for Control and Prevention said vaccine breakthrough cases are expected.
“COVID-19 vaccines are effective and are a critical tool to bring the pandemic under control. However, no vaccines are 100% effective at preventing illness in vaccinated people. There will be a small percentage of fully vaccinated people who still get sick, are hospitalized, or die from COVID-19,” it said in its guidance documents.
The CDC pointed out that COVID-19 vaccines are effective at preventing COVID-19 disease, especially severe illness and death and reduce the risk of people spreading coronavirus.
It recommends vaccinated people experiencing COVID-19 symptoms to get tested.
Low risk of reinfection
Meanwhile Public Health England’s weekly surveillance data on possible coronavirus (COVID-19) reinfections indicated the risk is low.
The report stated that there were 15,893 possible reinfections with SARS-CoV-2 up to 30 May 2021 in England, out of nearly 4 million people with confirmed infections throughout the pandemic.
“This is equivalent to around 0.4% cases becoming re-infected. Reinfection with SARS-CoV-2 is expected and has been previously reported, however, this data highlights that the overall risk, as detected through national surveillance, remains low. PHE is calling on everyone who is eligible for the COVID-19 vaccine to take up the offer of 2 doses as this will minimise the risk of re-infection,” the PHE report said.
A possible reinfection is identified where consecutive positive test results in the same person are at least 90 days apart, PHE said.
Current evidence suggests that most reinfections will not cause symptoms, the report stated, adding work is ongoing to better understand the factors that make someone more likely to catch COVID-19 again and also the impact of vaccine status.
“There is currently no evidence that the Delta variant, or any other Variants of Concern, are more likely to cause reinfection than others, but we will closely monitor this,” the PHE said.