The vaccine against COVID-19 has changed the course of the pandemic in the last year. Last November, when the previous edition of the refresher course of vaccinations took place, 11 projects were in phase 3 or were about to begin. But it would not be until 27 December that the European Medicines Agency (EMA) approved the first vaccine, the one made by Pfizer and BioNTech. Since then, the State has approved four vaccines. One of the questions tackled by the refresher course is the administration of combination vaccines. “We have presented different heterologous vaccination strategies, accompanied by the relevant studies”, explained Dr Magda Campins, Researcher of the Vall d’Hebron Research Institute Epidemiology and Public Health group and moderator of the course together with Dr Fernando Moraga Llop, a paediatrician of more than 40 years’ experience at Vall d’Hebron and currently, first deputy chairman of the Spanish Vacunology Association (AEV).

Studies already published support combination vaccines. If after obtaining the results of the Combivacs study, in which the Vall d’Hebron University Hospital participated, the go-ahead was given to administer the AstraZeneca and Pfizer combination, now it has the approval to combine Janssen with other vaccines, as well as the third or even fourth or fifth doses with different formulas. Julià Blanco, researcher at IrsiCaixa/IGTP, Hospital Germans Trias i Pujol, is the person selected to lead this presentation. In order to monitor the adverse effects of the vaccines and the combination of different formulas, it is necessary to have pharmacovigilance systems in place, such as those spoken of by the Professor of Pharmaco- Epidemiology at the University of Oxford, Daniel Prieto-Alhambra. “We know that the vector vaccines, such as AstraZeneca or Janssen, have been associated with cases of thrombosis and that the ARN messenger vaccines have been associated with myocarditis or pericarditis”, explains Dr Magda Campins.

Concerning the effectiveness of the vaccine against the SARS-CoV-2 variants, a topic that is currently under debate, discussed by Dr Josep M. Miró Meda, of the Hospital Clínic-IDIBAPS Infectious Diseases Department, Dr Magda Campins verified that “the current vaccines are efficient against the severe disease, but not enough prevent infection”. A study carried out by the Navarre Public Health Institute, which took place between April and October with the participation of 30,000 people, reveals that the current vaccines prevent hospitalisations and deaths, but do not prevent against a minor infection or becoming asymptomatic. As time passes from the inoculation of the second doses, the protection against infection decreases. It is calculated that the effectiveness falls to 59% in the fourth month.

These studies have opened the doors to third doses being administered. Dr Raúl Ortiz de Lejarazu, the doctor of the National Flu Centre spoke about  how, when and to whom it should be administered. As an expert flu microbiologist, he has reflected on whether in the future, the vaccine against COVID-19 will be proposed as a third, fourth or even fifth doses, whether we will use a booster only for vulnerable people or for the entire population.

Dr Isabel Ruiz Camps, of the Vall d’Hebron Infectious Diseases Department discussed the vaccination in an immunodepressed patient. Dr Montse Martínez, from the Preventive Medicine Department, assistant general manager of the Promotion of Health, spoke about strategies to capture special groups for them to be vaccinated. At present, 89% of the country’s population over the age of 12 is vaccinated.

The other new vaccines: the herpes-zoster virus, flu and meningococcus.

This course has also spoken about other new developments in vaccines other than COVID-19. Dr Fernando Moraga-Llop summarises the most significant new developments. The first is the new adjuvant inactive vaccine to combat herpes-zoster. Until now, there was an attenuated vaccine with limitations, because it could not be given to immunodepressed patients, who are those that most need it. “The new vaccine carries an adjuvant, a substance that increases the immune response”, explains Dr Fernando Moraga Llop. It has been designed with people over the age of 18 in mind with severe immunosuppressant problems and for those over the age of 50 on a systematic basis.

Another new development in Spain is the intranasal attenuate anti-flu vaccine. Dr Fernando Moraga-Llop proposes the possibility of administering it children who, in the case of flu, are the main transmitters.

Two anti-pneumococcal conjugate vaccines were presented: the15-valente and the 20-valente. These include two and seven additional serotypes, respectively, than Prevenar 13 that the EMA is expected to approve during 2022.