LONDON, June 4. -- British relief organizations acted urgently today to get anticholera vaccine to India, where an epidemic has broken out among refugees from East Pakistan.

Oxfam, a private charitable organization, is to fly out 800,000 doses of the vaccine tomorrow. Two other charities, War on Want and the Save the Children Fund, plan to send more next week - along with medicine and mobile hospitals.

Raymond Courmoyer, Oxfam's representative in eastern India, said here today during a brief visit that cholera threatened not only the estimated four to five million Pakistani refugees but also many Indians.

The administration of India's West Bengal State is appealing for four million cholera and typhoid shots, Mr. Courmoyer said. He termed the situation "a world tragedy" and said that the refugees, even apart from the cholera risk, were living "in a terrible state."

"MAJOR DISASTER" FEARED

A representative of War on Want, the Rev. Wilfred Kerr, said there would be a "major disaster" unless the refugees could return to their homes in East Pakistan before the monsoon rains start in about a month. "They are living in tents set up in rice fields, and they will be flooded out when the rains come," he said. "Dysentery and cholera will become rampant."

To assist the Indian Red Cross in surveying the health situation in the camps, the League of Red Cross Societies in Geneva is sending a medical expert to India.

W.H.O. SHIPPING SUPPLIES

The World Health Organization announced that the first planeload in a relief program of more than $300,000 worth of supplies would leave Geneva for India tomorrow.

The organization said it was acting in response to a request today from the Indian Director of Health. The shipments will include $40,000 in medical equipment previously donated by members of the agency, plus $100,000 in supplies purchased with W.H.O. funds and $185,000 donated by the office of the United Nations High Commissioner for Refugees for purchase of supplies.

The largest item will be 250 metric tons - or about 551,000 pounds - of rehydration fluid to treat loss or body fluids among cholera victims. Experts say fluid loss is the principal cause of deaths from cholera. The W.H.O. program Is also to include 500,000 doses or cholera vaccine, a million capsules of tetracycline antibiotic, 1,000 bottles of tetracycline syrup for children, 75,000 syringes and 300,000 disposable needles.