Covid-19: Pharmacies may have problems storing vaccines

The pharmaceutical companies responsible for two of the most promising vaccines against covid-19 do not anticipate difficulties in distribution operations, but storage at vaccination sites will be more complex and pharmacies are only prepared to receive one.

Last week, the pharmaceutical companies Moderna and the Pfizer / BioNTech consortium announced that their candidates are about 95% effective, placing themselves ahead of the covid-19 vaccine race.

With these new data, and other promising ones released in the meantime by more companies, expectations for a new vaccine increased in January, or even before the end of the year, and began to discuss the logistical challenges of a mass vaccination operation.

In Portugal, the vaccination plan, which includes logistical issues from distribution to storage, is being coordinated by a ‘task force’ created by the Government and should be known soon.

Lusa spoke with pharmaceutical companies that have been developing two of the vaccines that have already been provided by the European Union, Pfizer and Moderna, and none anticipates difficulties in terms of worldwide distribution operations.

Between the two, Moderna’s candidate is the one that, due to its characteristics, imposes less constraints, since it remains stable for up to six months at -20 ° C, equivalent to the temperature of most domestic or medical freezers.

“Using freezing temperatures between -25 ° C and -15 ° C is an easier and more conventional method of distribution and storage than deep-freezing and most pharmaceutical distribution operators already have the ability to distribute to the entire planet in these conditions, ”explained the American pharmaceutical company.

The deep-freezing process that Moderna refers to is, on the other hand, the one required for the conservation of the Pfizer / BioNTech vaccine, which must be stored at very low temperatures, between -70 ° C and -80 ° C.

But the consortium did not leave this difficulty unresolved and developed special thermal boxes, with a capacity of up to 4,865 doses, which allow the vaccine to be kept at the necessary temperature for 15 days, through the so-called dry ice (that is, solid carbon dioxide).

“Afterwards, the vaccine can be kept for another five days in the refrigerator at 2 ° C to 8 ° C until it is inoculated”, explained Pfizer Portugal’s director-general, Paulo Teixeira, adding that the coolers will be used by Pfizer during the distribution process to vaccination sites.

There, however, the storage of this vaccine will be more complex, considering the short period during which it can be kept in a conventional refrigerator.

Therefore, without resorting to deep freezing, not all points that, for example, now administer the flu vaccine may also have Pfizer BNT162b2. This is the case with community pharmacies.

“I would say that it will not be foreseen that this vaccine can be administered in pharmacies, not least because the information we have is that most pharmacies will not be able to have these refrigerators that allow storage up to -80 ° C”, said Paulo Teixeira, who stressed that Portugal has the necessary equipment so that the vaccine can be stored in other environments.

The same difficulty does not arise with the candidate of Moderna, which besides being stable at -20 ° C for six months, withstands higher temperatures between 2 ° C and 8 ° C for 30 days after thawing and remains stable at room temperature for 12 hours.

“This allows storage to be done in most pharmacies, hospitals and doctors’ offices”, explains the pharmacist in a reply sent to Lusa, adding that mRNA-1273 will also not require any special handling or dilution on the spot “which facilitates vaccination in a wider variety of settings ”.

Defining vaccination points is one of the tasks of the working group created by the Government, which is also responsible for defining the vaccination strategy, which includes the identification of priority target groups, administration and clinical follow-up of results and adverse reactions.

Regarding the effectiveness of the vaccine, the medical director of Pfizer Portugal, Susana Castro Marques, explained that the third phase of clinical trials, which involved about 44 thousand volunteers, between 12 and 85 years of age, at a rate of 95% announced last week was consistent across age groups.

“It is also known that over 65 years of age the effectiveness is greater than 94%”, he added, also stressing that, among the 44 thousand volunteers, about 41% were between 56 and 85 years old, so “there is a lot of information for older people.

The task force coordinator, Francisco Ramos, also told Lusa in the meantime that the proposal presented by DGS “has no age limit for people hospitalized in homes”.

“If it exists, it will be due to the characteristics of the vaccines themselves and not because of the choice of who has responsibility for deciding who should be vaccinated, namely who will be vaccinated in the first phase”, which will cover about one million people, he explained.

Last week, the prime minister said that the country is prepared to buy around 16 million doses of three vaccines and, according to Health Minister Marta Temido, one of the first may arrive as early as January.

Among the three vaccines, the doses to be purchased are already defined: in one 6.9 million, in another 4.5 million, according to António Costa, without identifying the laboratories. As for the third, of 4.6 million, it will be that of Pfizer / BioNTech, the pharmacist confirmed to Lusa.

Both Pfizer / BioNTech and Moderna have already signed contracts with the European Commission to ensure vaccines against covid-19, ensuring 200 million doses of the former (with the possibility of adding another 100 million) and 80 million doses of the second for now , which could go up to a total of 160 million.

In the case of the two vaccines, which both require two doses per person, the prices agreed with the European Commission are not yet known, but in August the prime minister promised a “progressive, universal and free vaccination”.

In addition to these, the European Commission has also signed contracts with AstraZeneca (300 million doses), Sanofi-GSK (300 million), Johnson & Johnson (200 million), and CureVac (405 million).

Original article available in Portuguese at http://postal.pt/