Data suggests that breastfeeding mothers who have been infected by Covid-19 continue to secrete virus neutralizing antibodies to their milk for as long as 10 months.
Researchers believe that these antibodies could be used to treat severe Covid-19-related diseases, which could prevent their progress.
Young children are at lower risk of contracting severe Covid-19 than people older or with underlying medical conditions. However, around one in 10 infants will need significant hospital care if they get infected.
This information is relevant to breastfeeding mothers. Knowing if antibodies are present in milk, how long they will protect after being infected and which vaccine will give your baby the best protection is important.
Although the antibodies found in breast milk differ from those in Immunoglobulin G antibodies (IgG), which predominate in blood, some are secreted into breastmilk. Secretory Immunoglobulin (IgA) is the main antibody. It sticks to babies' linings and prevents bacteria and viruses from entering their bodies.
Researchers had detected antibodies against SarsCoV-2 in breastmilk, but it wasn't clear if they could neutralise it or how long women would continue to produce them after coming into contact with coronavirus.
Powell and his colleagues collected breast milk from 75 women who had recovered after Covid-19. They found that 88% of them contained IgA antibodies. These antibodies were able to neutralize Sars-CoV-2 in most cases, which could have prevented infection.
Further tests revealed that these antibodies were still being secreted by women for as long as 10 months. This means that even if you breastfeed, the antibodies will still be present in your milk. Powell presented the findings at the Global Breastfeeding and Lactation Symposium held on 21 September.
She believes IgA antibodies from breast milk may also be beneficial for adults with severe Covid-19. This could be a great therapy because Secretory IgA is found in the mucosal area, which includes the lining of your respiratory tract. It survives and functions well there. It could be used in a nebuliser type treatment. This would make it very effective during the time when the patient is sick but not yet ready to go to intensive care.
Her team also examined the possibility of coronavirus-specific antibodies being transferred to breast milk by 50 women following vaccinations with the Moderna, Pfizer or Johnson & Johnson (J&J jabs). Moderna vaccine was administered to all women. 87% of the Moderna vaccine recipients had coronavirus specific IgG antibodies, while 71% and 51% had virus-specific IgA antibodies. Only 38% of J&J vaccine recipients had IgG antibodies, while 23% had IgA antibodies for coronavirus in milk.
Powell stated: We know that RNA vaccines produce a much higher level of antibodies than other vaccines. Although you don't necessarily need as much antibody to protect yourself from infection, the milk effect depends on having a high level of antibodies in your blood. The milk levels are very low because there is less stimulation by the J&J vaccine, a viral vector vaccine.
Now, the team is investigating the antibody response to AstraZeneca in breast milk.
