Cuban doctors and UNICEF officials are orchestrating vaccination efforts in Haiti against diseases that might spread in Haiti's post-quake tent cities.

Children are main vaccination targets and vulnerable adults will also get vaccine shots in temporary residence areas which are mostly large tents in open places.

So far there is no evidence that contagious diseases have broken out in the makeshift camps, but diseases caused by poor hygiene, like skin rashes and respiratory complaints are plentiful.

Red Cross officials worry about a potential cholera outbreak.

Cuban doctors have started vaccinating children in a clinic at the Silvia Cattor Stadium in the Haitian capital.

"The Cuban brigade is working alongside the Pan-American Health Organization, the World Health Organization and UNICEF on delivering vaccines for immune responsive infections," said Adelaide Grau Varela, a member of the Henry Reeve Cuban Medical Brigade that has already vaccinated close to 3,100 people against tetanus-diphtheria at the stadium.

UNICEF began collaboration with Cuban doctors on Monday to deliver vaccines to temporary residence areas where children are exposed to infectious diseases.

"We are aiming to reach 500,000 children in the quake area with vaccines," said Kent Page, senior UNICEF communications officer. "We will be expanding to three or four other sites this week. Because of the living conditions in the makeshift shelters a major disease outbreak would spread like wildfire. This is a preventative measure to save children's lives."

The Henry Reeve Cuban Medical Brigade, first formed in response to the United States' Hurricane Katrina emergency and with field experiences in China, Pakistan, Guatemala, Indonesia and Bolivia, plans to open 37 more vaccination points across Port-au-Prince and beyond.

The children will also receive vaccines against measles, rubella and pertussis, and vitamin A shots.