Chlamydia psittacosis can be transmitted from birds to people, through ventilation systems, by inhaling bird droppings, and by transmission from birds to intermediate host animals and then from the intermediate host animals to people. We reported psittacosis can cause chronic disease, including autoimmune diseases, multiple sclerosis, polyarthritis, psoriatic arthritis, lymphoma, and other types of cancer. We suggested chlamydia psittacosis could be an important risk factor in covid19, in generating mutations in Italy, and in disease severity (5/6/20, 5/26/20, 7/16/20). We reported psittacosis can cause transverse myelitis (7/26-27/19; 10/6/19), and suggested psittacosis is a potential cause of acute flaccid myelitis (2/17/19), alone or as a co-infection. Psittacosis can act synergistically to cause harm, when a person is co-infected with other viruses and bacteria.

A case of transverse myelitis was reported in one patient in the covid19 vaccine trials, in England, which caused AstraZeneca to temporarily halt the trial. A second patient may have developed MS, which was not confirmed as independent or related to the vaccine. Investigating and diagnosing underlying chronic infections in the covid-19 patient who developed transverse myelitis, and the patient who may have developed MS, could be important in evaluating the safety of the vaccine for the population at large.

Psittacosis and mycoplasma are known causes of acute transverse myelitis; and may be involved in development of multiple sclerosis. Chronic chlamydia psittacosis or mycoplasma may explain the case of transverse myelitis and the case of MS in the covid19 vaccine trial.  Testing for chronic infectious pathogens may be important in understanding covid19, and in understanding the risks and complications arising in clinical trials.