What you need to know
What you need to know

What you need to know

WHO Strategic Advisory Group of Experts on Immunization (SAGE) has posted updated temporary policy recommendations for the use of the Ad5-nCoV-S recombinant (Ad5-nCoV) vaccine against COVID-19. This article provides a summary of these preliminary recommendations; you can access the entire guide here.

Here’s what you need to know.

Who should be vaccinated first?

While the supply of COVID-19 vaccine is limited, high-risk healthcare workers and the elderly should be given priority for vaccination.

Countries can refer to WHO roadmap for prioritization and WHO Values ​​Framework as a guide for their prioritization of target groups.

The vaccine is not recommended for people under 18 years of age, awaiting the results of further studies in that age group.

Who else can take the vaccine?

Vaccination is recommended for people with comorbidities or certain health conditions that have been identified that increase the risk of severe COVID-19, including diabetes mellitus, obesity, cardiovascular disease, and neurodegenerative diseases.

The vaccine can be offered to people who have previously had COVID-19. The optimal time interval between a natural infection and vaccination is not yet known. People who have had a previous infection can choose to postpone the vaccination for 3 months after the infection. As more evidence becomes available, the length of this time period may be revised as well as the number of doses needed.

SAGE recommends that moderately and severely immunocompromised individuals be offered an additional (ie, second) dose as part of the primary series 1-3 months after the first dose. This is because this group is less likely to respond adequately to vaccination after standard primary vaccination series and has a higher risk of severe COVID-19, regardless of age.

For the purposes of this preliminary recommendation, moderately and severely immunocompromised individuals include persons with active cancer, transplant recipients, immunodeficiency and active treatment with immunosuppressants. It also includes people living with HIV with a current CD4 cell count of <200 cells / µl, signs of an opportunistic infection, not in HIV treatment, and / or with a detectable viral load (ie advanced HIV disease) .

Should pregnant women be vaccinated?

The available data on the Ad5-nCoV vaccine for pregnant women are insufficient to assess either the efficacy of the vaccine or possible vaccine-related risks during pregnancy. However, based on previous experience with other vaccines during pregnancy, the efficacy of the Ad5-nCoVAd5-nCoV vaccine in pregnant women is expected to be comparable to that observed in non-pregnant women of the same age. Further studies are expected to evaluate the safety and immunogenicity of pregnant women.

Meanwhile, the WHO recommends the use of the Ad5-nCoV vaccine for pregnant women when the benefits of vaccination for the pregnant woman outweigh the potential risks. To help pregnant women make this assessment, they should have information about the risks of COVID-19 during pregnancy; the likely benefits of vaccination in the local epidemiological context; and the current limitations of safety data in pregnant women. WHO does not recommend pregnancy testing before vaccination. The WHO does not recommend postponing the pregnancy or considering terminating the pregnancy due to vaccination.

The WHO recommends the same use of the Ad5-nCoV vaccine during breast-feeding as in other adults. WHO does not recommend stopping breastfeeding after vaccination.

Who is the vaccine not recommended for?

A history of anaphylaxis to any component of the vaccine is considered a contraindication to vaccination.

Individuals with an immediate non-anaphylactic allergic reaction to the first dose (ie hives, angioedema without respiratory symptoms or symptoms occurring within 4 hours after administration) should not receive additional doses unless recommended after review by a healthcare professional with specialist expertise. . Similarly, anyone who experienced thrombotic thrombocytopenic syndrome (TTS) after the first dose of this vaccine should not receive a second dose of the same vaccine.

People with acute PCR-confirmed COVID-19 should not be vaccinated until they have recovered from acute illness and the criteria for terminating isolation are met.

What is the recommended dose?

SAGE recommends the use of Ad5-nCoV vaccine as a single dose (0.5 ml) given intramuscularly into the deltoid muscle.

Can this vaccine be ‘mixed and matched’ with other vaccines?

Ad5-nCoV booster dose following a primary series of the inactivated COVID-19 vaccine developed by Sinovac (CoronaVac) was associated with higher vaccine efficacy compared to a homologous CoronaVac booster. The Ad5-nCoV vaccine can be used as a booster dose after a completed primary series with any other EUL COVID-19 vaccine.

Heterologous boosters should take into account current vaccine supply, vaccine supply forecasts and other access considerations along with the potential benefits and risks of the specific products used.

How is this vaccine compared to other vaccines already in use?

We can not easily compare vaccines among themselves due to different approaches to the design of the respective efficacy and efficacy studies, but overall, all the vaccines that have achieved the WHO’s list of emergencies can be considered safe and highly effective in preventing serious illness and hospitalization due to COVID-19.

Is it safe?

SAGE has thoroughly assessed the data on the quality, safety and efficacy of this vaccine and has recommended its use to persons aged 18 and over.

Thrombosis with thrombocytopenia syndrome (TTS), a very rare syndrome of blood clotting combined with low platelet count, has been reported approximately 3-30 days after vaccination with Ad5-nCoV. A causal relationship between the vaccine and TTS is considered plausible, although more evidence is needed to confirm this.

In countries with ongoing SARS-CoV-2 transmission, the benefits of vaccination to protect against COVID-19 far outweigh the risks of TTS. However, assessments of benefits and risks may vary from country to country. As part of the EUL process, CanSino is committed to continuing to submit data on safety, efficacy and quality in ongoing vaccine trials and roll-out in populations, including in older adults.

How effective is the vaccine?

Data from clinical trials showed that the Ad5-nCoV vaccine had an effect of 64% against symptomatic disease and 92% against severe COVID-19.

Does it work against new variants of SARS-CoV-2 virus?

The primary clinical trial of this product was completed in January 2021, prior to the emergence of Delta and Omicron variants. There are still insufficient data for these newer variants.

SAGE currently recommends using this vaccine according to the WHO’s priority roadmap.

Does it prevent infection and transmission?

As recent data suggest a limited effect of the vaccine on transmission, particularly against Omicron, it is advisable that public health and social measures to reduce SARS-CoV-2 transmission should be considered. These measures include wearing a mask, physical distance, hand washing, respiratory and cough hygiene, avoiding crowds and ensuring adequate ventilation in accordance with local national guidelines.

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