A Cork GP has said that the news of another vaccine shown to be more than 90% effective is exciting but that “there are some obstacles to overcome before a vaccine will eliminate Covid-19”.
US firm Moderna has said its experimental vaccine was 94.5% effective in preventing Covid-19, based on interim data from a late-stage clinical trial.
The firm's final-stage clinical trial is ongoing and includes more than 30,000 people in the US.
The interim analysis included 95 participants with confirmed cases of Covid-19, of which 90 had received the placebo and five the active vaccine.
Severe cases of coronavirus were also examined, including 11 severe cases in the first interim analysis.
All 11 cases occurred in the placebo group and none in the group which had received the vaccine, known currently as mRNA-1273.
It is the second US company in a week to report results that exceed expectations after Pfizer and its German partner BioNTech announced their vaccine was 90% effective.
Dr Fiona Kelly of Bank Place Clinic in Castletownbere said that although the news of two vaccines with efficacies that have surpassed expectations gives people a welcomed lift and some hope that there is light at the end of the tunnel during Level 5 restrictions, that it must be remembered that the clinical trials have not yet been completed.
“Before getting my hopes up about the vaccine, there are a few questions I would like to know the answers to: How long will protection from the vaccine last? Will it be effective for everyone including people with multiple comorbidities? Is it too early to tell of any potential side-effects? Will the vaccine result in the prevention of transmission of Covid-19?
“Also there are some obstacles to overcome before a vaccine will eliminate Covid-19. In order to achieve herd immunity and consequently suppression of the virus, it is estimated that 60 to 70% of the world's population would have to be vaccinated. The logistics of this are huge and it would require a vast worldwide immunisation programme,” Dr Kelly said.
An advantage of Moderna's vaccine is that it does not need the same cold storage as Pfizer's vaccine.
Moderna expects it to be stable at standard refrigerator temperatures of 2C to 8C for 30 days and it can be stored for up to six months at -20C compared to Pfizer's vaccine which must be shipped and stored at -70C.
Dr Kelly said the fact that the Moderna vaccine is expected to remain stable at a temperature of -20C for six months and can be stored in a standard refrigerator for up to 30 days “definitely places it in a more advantageous position compared to the Pfizer vaccine as I think it would allow for easier distribution and availability”.
She said that if existing challenges in relation to vaccines are overcome, that “it will take some time before we can effectively eliminate this novel virus”.
“The news on the vaccine is exciting but I think it's too soon to get too excited,” she said.